Tenth Doctor

The Tenth Doctor was the tenth incarnation of the Doctor. Unlike his immediate predecessor, who was plagued by melancholy due to his actions during the Last Great Time War, this incarnation was much more outgoing and genial, a demeanor that hid the "survivor's guilt" that had plagued him since the war. Throughout his life, however, the weight became much more pronounced, haunted by companions lost, enemies believed long-dead and events that threatened the fabric of time itself. He met his end after he absorbed a huge quantity of nuclear radiation whilst saving the life of his friend, Wilfred Mott, leading to his regeneration into his next incarnation.

Regeneration
When the Doctor absorbed the TARDIS' Time Vortex from his companion, Rose Tyler, the forces contained in himself began to destroy every cell in his body. He regenerated for a ninth time to save his life. The Doctor had dematerialised the TARDIS from its location on Satellite 5, intending to fulfill his promise to take Rose to the planet Barcelona in the year 5006. With Rose suffering an emotional crisis over the Doctor's sudden change, the Doctor instead took pity and headed back to the Powell Estate in London on Christmas Eve 2006 after convincing her of his identity by reminding her of the first thing he said to her. Before he could successfully complete the landing, he began to suffer adverse effects from the violence of his physical change and experienced manic hyperactivity, sending the TARDIS to such dangerous extremes of speed that it crash-landed. Shortly afterwards, his memory took a turn for the worse and he dazedly wished Jackie and Mickey a merry Christmas before promptly lapsing into a coma. He snapped out of it briefly in order to save Rose from a killer Christmas tree, but the stress of waking up too soon made matters worse, and he soon collapsed again. He eventually recovered in time to beat back an invasion of Earth by the Sycorax on Christmas morning. During this adventure, he had his hand cut off while in a sword fight with the Sycorax leader. Still retaining enough cellular energy from his regeneration, he grew it back. (DW: The Christmas Invasion)

New Adventures with Rose
The Doctor and Rose embarked on more adventures together through time and space. They came to New Earth and were summoned to the New New York Hospital by the Face of Boe. While there, he stopped the Sisters of Plenitude, who were creating Humans and infecting them with every disease. During this time, Rose was possessed by Cassandra, who was trying to extend her life, but the Doctor eventually convinced Cassandra to "end it". (DW: New Earth) They then took a trip to 1879, Scotland. There the Doctor and Rose stopped a werewolf from biting Queen Victoria and starting the Empire of the Wolf. As a reward, the Doctor was knighted "Sir Doctor of TARDIS" and Rose was knighted "Dame Rose of the Powell Estate". They were then banished from the British Empire, since their blasé attitude to danger unnerved the Queen. The Doctor also inadvertently inspired Queen Victoria to found the Torchwood Institute, dedicated to defending Britain from the alien threat. (DW: Tooth and Claw)

Back on 21st century Earth, the Doctor went undercover as John Smith, a physics teacher at a school which the Krillitane had infiltrated. The Doctor had a chance reunion with his past companions Sarah Jane Smith and K-9. The Doctor also allowed Mickey Smith to accompany him and Rose on their travels, on Sarah Jane's suggestion. (DW: School Reunion)

The Doctor, Rose and Mickey next found themselves in a 51st century ship, which was connected to 18th century France. There he met a pre-teen Jeanne-Antoinette Poisson. The Doctor saved her as a child from the ship's Clockwork Droids and several more times in her life. After the droids were stopped, he offered to allow her to travel with him, but he made a mistake and returned to her after she died. (DW: The Girl in the Fireplace)

On a parallel Earth, the Doctor, Rose and Mickey witnessed the birth of that universe's Cybermen. The adventure ended with Mickey deciding to stay in the parallel universe, leaving Rose and the Doctor to continue their travels together. (DW: Rise of the Cybermen/The Age of Steel)

The Doctor and Rose planned to see an Elvis concert, donning the outfits of the 1950s and riding a scooter out of the TARDIS, however, they accidentally ended up in England, June 2, 1953, where the Wire was planning to steal the essences and faces of everyone watching the coronation on television. Rose fell victim to the Wire, but during the coronation the Doctor defeated the Wire, restoring the faces of its victims. (DW: The Idiot's Lantern) The Doctor and Rose then travelled to the planet of Krop Tor, an impossible planet that orbited a black hole and inhabited by Sanctuary Base 6. The Humans of Sanctuary Base 6 had journeyed to Krop Tor to discover the source of power emanating from the planet's core, which was allowing the planet to orbit a black hole without falling in. The Doctor and a researcher from the crew of Sanctuary Base 6, named Ida Scott, descended into the core of the planet to explore. There they discovered a pit, into which the Doctor went, alone. Once he'd reached the bottom, he found himself face-to-face with the Beast. The Beast had been terrorizing the explorers on the surface and possessing their servants, the Ood. The Doctor trapped the Beast by imprisoning it in the black hole and was joyfully reunited with Rose and the TARDIS. (DW: The Impossible Planet/The Satan Pit)

Some time later, he and Rose were in a fight with a Hoix, an event seen by Elton Pope. When Elton later upset Rose's mother, the Doctor and Rose confronted him, as well as helped him defeat the Abzorbaloff. (DW: Love & Monsters)

He and Rose then travelled to 2012 to see the London Olympics. He met a girl named Chloe Webber who had been possessed by a lone Isolus. Chloe was trapping other children from her street in drawings to stop the Isolus from feeling lonely. After briefly being trapped in a drawing himself, along with the TARDIS, the Doctor ran with the Olympic torch to the stadium, lit the Olympic flame, and then reunited with Rose. (DW: Fear Her)

The Pain of Loss
When the Doctor and Rose returned to present-day London, they found that the entire planet was being visited by beings believed to be ghosts. The Doctor tracked the signal to Torchwood Tower and was subsequently taken prisoner by the Torchwood Institute. He strongly opposed their use of "ghost shifts" for a power source, as it was ripping a hole between parallel worlds which increased in size with every "ghost shift". The original tear was caused by "the Sphere", an object the Doctor identified as a Void Ship. Later, three computer technicians, who were secretly under the control of Cybermen, restarted the ghost shift. This led to the realisation that the ghosts were actually Cybermen, coming through from the parallel world where the Doctor and Rose had left Mickey. As the Cyberman invasion of Earth began, the Void Ship opened, revealing the Cult of Skaro, a group of Daleks with a Genesis Ark. The Genesis Ark was Time Lord technology which contained millions of Daleks that had been imprisoned by the Time Lords. In order to save both dimensions from annihilation and defeat the Daleks and Cybermen, the Doctor decided to open the Void. This opening would suck anything covered in "Void stuff" into it. Realising that himself, Rose and the others were also covered in Void stuff, the Doctor sent Rose, against her will, to the parallel world, along with Mickey, Pete Tyler and her mother, where they all would be safe from the Void. However, Rose returned, refusing to leave the Doctor and knowing that in making her choice she would never see her family again. Together, the Doctor and Rose opened the Void and the Daleks and Cybermen were sucked in. The plan initially went smoothly, until Rose's lever malfunctioned, threatening to halt the process. Rose managed to secure the lever but couldn't hold on and was almost sucked into the Void, much to the Doctor's terror and despair. Rose was saved at the last second by her parallel father and taken back across to the parallel universe, separating her from the Doctor. The Doctor and Rose were able to meet one last time on Dårlig Ulv Stranden in Norway. The Doctor had parked the TARDIS in orbit around a supernova for enough power to project an image through the last gap between the universes to say goodbye. Rose was able to confirm her love for the Doctor to him, but the Doctor was cut off before he could tell her he loves her. (DW: Army of Ghosts / Doomsday)

A Noble Encounter
Whilst he was grieving over Rose, a bride named Donna Noble, to the Doctor's shock, appeared inside the TARDIS during her wedding ceremony. The Doctor discovered the involvement of the ancient Racnoss and defeated them. After the Doctor's destruction of the Racnoss, and largely because of the Doctor's merciless treatment of them, Donna decided not to travel with him and left after advising the Doctor to "find someone". (DW: The Runaway Bride)

An Old and Best Friend
Sometime after meeting Donna, the Doctor, travelling alone, landed on the Slough of the Disjointed Planets, an area of space populated by warlike races renowned for their brutal conflicts. There he encountered the dying War Keeper, the ancient controller of the population of the Disjointed Planets. In an attempt to find a worthy successor, the War Keeper scanned the Doctor's mind for the identity and location of the greatest leader of the cosmos, and chose Brigadier Lethbridge-Stewart. The old soldier, now retired and in his late 70s, found himself transported to the Slough to receive the position, but refused to accept the role. As an alternative, the War Keeper, using the Doctor's memories, choose as an alternative Mike Yates, but accidentally summoned to the Disointed Planets another, far less capable man with the same name. Rivals of the dying War Keeper infiltrated his helpers before his death and passed onto the other Mike Yates the Keeper's control device, the Warkeeper's Crown. With the weak-minded wrong Yates under control of the Crown, and with the wrong Yates in turn in control of the numerous forces of the Disjointed Planets, the deceased War Keeper's rivals planned to control the conflicts. The controlled Yates transported himself back to his home on Earth, along with many Orcs, Hawks, and other creatures. The Doctor and the Brigadier, with an army of Brigadier-clones the Doctor created with technology at the Slough, returned to the Earth to defeat the demon hordes and free Yates from the Crown's control. During this time, the Mike Yates whom the Doctor and the Brigadier knew of old, witnessed the conflict. With the danger passed, the Doctor and the Brigadier, still and ever the best of friends, re-lived their old glories, and said their good-byes, although the Brigadier expected to see his old friend once more. (DWM: The Warkeeper's Crown)

Smith and Jones
The Doctor met Martha Jones, a London medical student, and, after defeating a Plasmavore on the Moon, invited her to travel with him in the TARDIS. (DW: Smith and Jones) They arrived in Shakespearean London and foiled the Carrionites, discovering the mystery of Love's Labour's Won. (DW: The Shakespeare Code) He then broadened Martha's trip to one to the past and one to the future after being chased out of the time. They next landed on New Earth, which he had previously visited with Rose. The Doctor helped to save thousands of people from the motorway before hearing the final words of the Face of Boe, "You are not alone". (DW: Gridlock) In 1930s New York City, the Doctor once again met and defeated the Cult of Skaro, though Dalek Caan escaped. (DW: Daleks in Manhattan)

Together, Martha and the Doctor put an end to the work of mad Professor Lazarus, (DW: The Lazarus Experiment) and following that helped save a spaceship from plummeting into a sun. (DW: 42) Later, the Doctor hid from the Family of Blood, a family of aliens who wanted his Time Lord body. He used a Chameleon Arch to transform himself mentally and physically into a Human school teacher named John Smith, hiding completely his Time Lord self so that his alter ego had no recollection of the Doctor. John Smith subsequently fell in love, much to the disappointment of Martha, with the matron of the school, Joan Redfern and would have spent the rest of his life with her. However, the Doctor was forced to retake his Time Lord body to save the Earth from destruction, and sought suitable punishment for the Family of Blood. (DW: Human Nature/The Family of Blood)

The Doctor and Martha travelled to 2006 to investigate strange disappearances at an old abandoned house. They were transported back in time to 1969 by aliens in the form of stone angels who fed off their potential energy. Using information given to him by Sally Sparrow prior to the incident, he left messages for Sally in the future to bring the TARDIS back to 1969. (DW: Blink)

A Lord's Return
In Cardiff, the Doctor "refuelled" the TARDIS using the Cardiff rift. Captain Jack Harkness jumped onto and physically clung to the exterior of the TARDIS, hitching a ride to the planet Malcassairo in the extremely far distant future. On Malcassairo, the Doctor found Professor Yana, who was actually his most fearsome nemesis, The Master. The Master had been made Human by another Chameleon Arch, but when Martha questioned his old fob watch, he opened it and became the Master again. After being shot by Professor Yana's assistant, Chantho, and facing imminent regeneration, the Master locked himself inside the Doctor's TARDIS and despite the pleas of his fellow Time Lord, hijacked the ship and escaped, leaving the Doctor, Jack and Martha to die at the hands of the Futurekind. (DW: Utopia) They were able to escape to the present when the Doctor used his sonic screwdriver on Jack's broken Vortex Manipulator. (DW: The Sound of Drums)

Using the human name of Harold Saxon, the Master became Prime Minister of Great Britain and invited an army of Toclafane to invade the world. (DW: The Sound of Drums) The Master imprisoned the Doctor for a year, during which time he used his laser screwdriver to artificially age the Doctor 900 years, turning him into a small creature. The Master was later defeated by manipulation of his Archangel Network, to the Doctor's own advantage. The Doctor displayed great powers during this period, using the psychic energy of the Earth's people, who had been told by Martha to think of the Doctor at a specific moment. He restored his young appearance and manipulated the powers to grant him almost god-like abilities. After disarming the Master, he approached and forgave him. The Master threatened to self-destruct his war fleet and take the Earth with him, but the Doctor knew that doing so would require the Master to sacrifice himself, which he couldn't do. The Master reluctantly surrendered and the Doctor was able to reverse time, trapping the Toclafane at the end of the Universe and reversing the Master's control over Earth. Subsequently, the Doctor decided to attempt to rehabilitate the Master, planning to keep him a prisoner aboard the TARDIS. The Master was shot soon afterwards by his Human wife, Lucy Saxon, who sought revenge for his cruel treatment of her. At the thought of becoming the Doctor's captive, the Master refused to regenerate and died for, supposedly, the final time in the arms of the Doctor, thus leaving the Doctor truly the last Time Lord in existence.

Following the events of the Year That Never Was, Martha left the Doctor, believing that she needed to live her own life and be with her family. Her family had been tortured at the hands of the Master and Martha felt partly responsible for their suffering. Not only that but, almost from their first encounter, Martha had fallen in love with the Doctor. However, she knew that her love was unrequited and that he only saw Rose when he looked at her. Martha explained this to the Doctor and they parted amicably. (DW: Last of the Time Lords)

When Incarnations Meet
Shortly after Martha left, the Doctor accidentally crashed his TARDIS with that of one of his fifth incarnation. He was able to use his memory of the event from when he was in his fifth incarnation to separate the TARDISes. However, before the tenth Doctor could turn the TARDIS' shields back on, the spaceship Titanic crashed in through the walls. (DW: Time Crash)

A Titanic Adventure
After fixing the damage to his TARDIS, the Doctor transported it inside the ship, where he decided to join the party. He quickly made a new friend, Astrid Peth, on board the Titanic. When the ship's owner, Max Capricorn, had a meteor shower purposely crash into the Titanic, the Doctor attempted to save the passengers. He could only save Astrid by transforming her into a being of light, but managed to save three other people. The Doctor stopped the Titanic from crashing into Earth. Additionally, he refused to allow the ship's tour guide Mr. Copper to travel with him and instead left him on Earth with a large amount of money. Following the incident, the Doctor set out on his own once again. (DW: Voyage of the Damned)

A Noble Reunion
While investigating Adipose Industries, the Doctor was reunited with Donna Noble, who finally accepted his invitation to travel with him. The Doctor and Donna were both quick to rule out the possibility of a romantic involvement, giving their companionship a different dynamic to that of the ones the Doctor had previously experienced with Rose and Martha. (DW: Partners in Crime)

During their travels, the Doctor realized he was responsible for the eruption of Mount Vesuvius and the destruction of Pompeii, in order to avert world domination by the Pyroviles. (DW: The Fires of Pompeii) He also helped set free the enslaved Ood of the Second Great and Bountiful Human Empire, (DW: Planet of the Ood) and disrupted a Sontaran invasion on Earth, during which time he was reunited with Martha Jones. (DW: The Sontaran Stratagem/The Poison Sky)

Directly following this, the TARDIS transported the Doctor, Donna and Martha to the planet Messaline in the far distant future, where his DNA was stolen and replicated to produce Jenny, his biological daughter. Initially critical of the girl due to her strong predilection for violence, the Doctor came to love his daughter, and mourned her "death" at the hands of General Cobb. He overcame his desire for revenge, however, in order to help found a new society on the planet. (DW: The Doctor's Daughter)

Some time after this, the Doctor and Donna visited 1926 and met the famed author Agatha Christie. They became embroiled in a murder mystery, ultimately saving Christie from a Vespiform, which resulted in Agatha losing some of her memories. (DW: The Unicorn and the Wasp)

Another important woman in the Doctor's life was introduced to him in the Library, Professor River Song. Song claimed to know the Doctor from a point in his future. (DW: Silence in the Library) She displayed knowledge of the Doctor's real name, as she revealed prior to sacrificing herself to save the Data Ghosts trapped in the Library's core. The Doctor, inspired by her faith in him, was able to save River Song by preserving her ghost in the core's virtual reality. It was on this adventure that the Doctor also discovered that his powers were developing beyond a Time Lord's usual limits. (DW: Forest of the Dead)

The Doctor and Donna later visited the leisure planet Midnight. Donna stayed at the leisure palace whilst the Doctor took a four-hour shuttle bus ride to the Sapphire Waterfall. The bus was subsequently attacked by an unknown entity which possessed one of the passengers, Sky Silvestry and eventually the Doctor, with the aim of inciting mass hysteria among the other passengers. Before the creature could trick the passengers into throwing out the Doctor, Sky was dragged out into the X-Tonic sun by the bus' hostess, who realized that Sky was stealing the Doctor's voice, and the creature departed, its plans defeated. (DW: Midnight)

Return of the Bad Wolf and Davros
The Doctor and Donna visited the Chinese-influenced planet of Shan Shen. When Donna went to get her fortune told, a member of the Trickster's Brigade created an alternate universe around her, one in which Donna never met the Doctor. In this alternate universe she met Rose Tyler, who told her two words to tell the Doctor. After Donna corrected the universe, she was able to tell the Doctor the two words: "Bad Wolf". (DW: Turn Left) The Doctor rushed back to Earth. He found that everything was normal, but when they re-entered the TARDIS, the whole planet was stolen. Finding no clue as to where the Earth was, he went to the Shadow Proclamation and learned that 27 planets including Earth had been stolen. With help from Harriet Jones, Jack Harkness, Sarah Jane Smith, Luke Smith, Martha Jones, Mr Smith and Rose Tyler, his Children of Time, he was able to be contacted and managed to lock on to the location of the Earth. After talking with his friends and Davros, who had been saved by Dalek Caan from the Last Great Time War, he landed on Earth. While talking to Donna, Donna pointed out that Rose was behind him. He turned around and the two began to run towards each other. A Dalek then emerged from the shadows and fired at him before being destroyed by a teleporting Jack Harkness. It was only a glancing blow, but was enough to mortally wound him. The Doctor was taken back into the TARDIS, where he began to regenerate. (DW: The Stolen Earth) Using his nearby severed hand, he used the regeneration to heal himself, but not to regenerate into a new form. The TARDIS was taken on board the Dalek Crucible where the Doctor, Rose and Jack were captured. Donna was locked inside the TARDIS, which was sent to be destroyed. As a result of this, a new Doctor was born from his severed hand when Donna touched it. The meta-crisis made Donna part-Time Lord, becoming the DoctorDonna of the Ood prophecy. DoctorDonna disabled the planet powered Reality Bomb to stop Davros from destroying the entire universe and then the three Doctor's sent the planets back to their original time and space. The Doctor was horrified by the actions of the new Doctor, who wiped out the last remaining members of the Dalek race, knowing they had the numbers to take the universe by force.

As the Doctor's companions fled to safety in the TARDIS, the Doctor offered to save Davros and Caan. Davros refused, hatefully denouncing the Doctor as "The Destroyer of Worlds", while Caan predicted that one of the Doctor's companions would perish. The Children of Time used the TARDIS to tow Earth back to its original point in time and space. The Doctor said his goodbyes to Sarah Jane, Martha, Jack and Mickey before he left the new Doctor in a parallel world, hoping that Rose and the new Doctor would be able to help each other. The new Doctor was able to tell Rose that he loved her and they kissed. Upon returning to his own universe, the Doctor was forced to remove all of Donna's Time Lord abilities and memories of traveling with him, as they would have eventually killed her. He returned Donna to her mother and grandfather, and told them that they would have to make sure she never remembered him. (DW: The Stolen Earth / Journey's End)

Invasion of the Mind
Es'Cartress of the Tactire, an inhabitant of Callufrax Minor, had been stuck on the Crucible and was unable to return home before the Doctors returned the planets. As such, he had to escape to the TARDIS. He then attempted to take over the Doctor's mind, but his link with the TARDIS forced them both into the Matrix. The Doctor was shown to have the stronger mind and was able to take control, killing Es'Cartress. (IDW: The Forgotten)

Walk of the Cyberking
Some time after leaving Donna, the Doctor travelled to London on Christmas Eve, 1851. Whilst there, the Doctor met a man calling himself "the Doctor" and at first assumed him to be his future incarnation. In reality, he was a Human, Jackson Lake, who had the contents of an infostamp about the Doctor imprinted on his brain. Jackson and his companion, Rosita Farisi, aided the Doctor in stopping the plot of the Cybermen and their ally, Mercy Hartigan. London was saved, Lake was reunited with his son, and invited the Doctor to share Christmas dinner with his new family, an offer which was at first declined, then accepted by the Doctor. (DW: The Next Doctor)

Final Adventures
Sometime after his adventure with Jackson Lake, the Doctor travelled to London in 2009 at Easter, investigating strange readings on a bus. While he investigated, the bus was hurtled through a wormhole and reappeared on San Helios. On the bus, he met yet Christina de Souza, and embarked on a mission with her to return the bus and its occupants to Earth and stop the Swarm from invading. Before leaving in the TARDIS, the Doctor rejected Christina's offer of companionship, stating that he had lost everyone who travelled with him and he had swore never again. Carmen, a low level psychic who aided the Doctor, gave him a prophecy. She told him "Your song is ending sir, It is returning. It is returning through the dark, oh but then... He will knock four times". Christina was arrested for multiple thefts, but the Doctor used his sonic screwdriver to aid her escape in the bus. When the Doctor was about to be arrested for helping Christina, he entered the "police box" to "arrest himself" and left. (DW: Planet of the Dead) At some point the Doctor crashed Sarah Jane Smith's wedding. He knew the Trickster, an old enemy of hers, would try and get his revenge on her after she had foiled the Trickster's previous attempts to cause chaos. As he arrived, Sarah Jane and her future husband Peter Dalton were taken by the Trickster. He was teleported to a nether realm along with Rani, Luke and Clyde, whom he had heard all about from Sarah Jane. He fought the Trickster, who hinted about his death, stating that "the gate is waiting". The TARDIS gave Clyde the power to control Artron energy by mistake, so he could have defeated the Trickster, while the Doctor informed Sarah Jane what needed to be done. Peter, Sarah Jane's fiancé, sacrificed himself to destroy the Trickster, leaving Sarah Jane alone and heartbroken. When the world was put back to normal, the Doctor visited 13 Bannerman Road and let Sarah Jane and her friends look inside TARDIS, after which he said farewell while sincerely asking Sarah Jane to never forget him. (SJA: The Wedding of Sarah Jane Smith) The Doctor, deciding to go to the planet Mars, met the crew of Bowie Base One, including Adelaide Brooke who served as his companion for a short time. He knew the crew of Bowie Base, and that everyone would die, as it was one of the most important events in the expansion of Humanity through the universe. He learned that the crew died due to the Flood, which possessed six of them. Initially unwilling to interfere due to his belief that the event was a fixed point in time, Adelaide's death causing her granddaughter to be inspired and explore the stars, he changed course once he remembered the deaths he had lived through and what it had left him with. He saved Adelaide, Mia and Yuri and took them back to Earth 2059. Adelaide was angry at the Doctor's interference and scolded him for thinking himself above obeying history's course. Adelaide then entered her home, apparently having given up trying to defy the Doctor, but committed suicide. The Doctor's memories of the day's events changed to fit in with the new timeline created. Distraught at the impossibility of his task of changing history, he began to ponder his own end when a vision of Ood Sigma appeared before him. It was this that made the Doctor realize that he had gone too far. As he then entered the TARDIS, the Cloister Bell rang. With a defiant "No!" he activated the TARDIS. (DW: The Waters of Mars) Sometime after leaving 2059, the Doctor visited America in 1958. While there, he visited a diner, meeting Cassie Rice and Jimmy Stalkingwolf. The Doctor examined a piece of "space junk" from the Roswell Crash eleven years ago. He accidentally activated it, drawing the attention of the android, Mister Dread. Escaping, the Doctor, Cassie and Jimmy were then attacked by a Viperox battle drone, which was promptly blown up by the United States military. The three were then taken to Area 51. They encountered Colonel Stark, who dismissed the Doctor's warnings about the Viperox, and attempted to have the Doctor and his companions mind-wiped. The attempt was unsuccessful, and the trio soon escaped, discovering a small grey alien along the way. They escaped to the town of Solitude and took shelter in a deserted building. Jimmy was then kidnapped by the Viperox, forcing the Doctor and Cassie to follow. They found Jimmy in the presence of a Viperox Queen before escaping into the desert, where they were confronted by four members of the Alliance of Shades who were destroyed by Jimmy's father, Night Eagle. Night Eagle took them to Rivesh Mantilax, the husband of Seruba Velak, the grey alien captive in Area 51. Colonel Stark then captured them all and took them back to Area 51. They Doctor then ran off with the "space junk", which was actually a weapon capable of destroying the Viperox. He was cornered on the roof by the Colonel, but convinced him to turn against the Viperox. The Viperox then invaded America but were beaten back by the Doctor. Before they retreated, the Viperox commander Lord Azlok snarled "Your day will come, Doctor!", reminding the Doctor of his ever-approaching fate. He departed soon after, leaving Cassie and Jimmy with a suggestion to start dating. (DW: Dreamland)

Vale Decem
However, the Doctor spent an unknown amount of time avoiding answering the Ood's summons, during which time he even got married. After meeting with the Ood on their home planet, the Doctor learned of the Master's resurrection on Earth, and raced to stop it, only to arrive too late. After discovering the Master living in the wastelands of London, he tried to confront him, only to be reunited with Wilfred Mott. He and Wilfred went to a London Cafe, where the Doctor informed Wilf that he was going to die, remarking on how he had become fond of his present incarnation and that even if he regenerated, he still saw it as dying as his current self was lost and a new one took his place. The Doctor left shortly after seeing Donna, who was now engaged to Shaun Temple. At night, the Doctor tracked down the Master once again, who stunned him with lightning from his hands, and forced him to listen to the "drums" in the Master's head, which the Doctor realised was not just the Master's insanity. Soon after, the Master was abducted by Joshua Naismith's private army. The next morning, the Doctor contacted Wilf, who informed him of Naismith and went with him in the TARDIS to the Naismith Estate. In the Manor's basement, the Doctor used the sonic screwdriver to unveil two Vinvocci, Addams and Rossiter, who informed him of the Immortality Gate's true purpose. The Doctor rushed to stop the Gate's activation, but was unable to, and the Master turned the entire Human race in copies of himself.

Now captured by the Master, the Doctor attempted to reason with the Master, who realised that with six billion people now hearing the drums, he could trace it to its source. Wilf and the Doctor were then rescued by the Vinvocci, who took them to their ship, which the Doctor then took offline to stop the Master finding them. While trying to repair the ship, Wilf tried to give the Doctor his gun, which the Doctor initially refused. When White-Point Star appeared in space and landed on Earth, the Master identified it only found on Gallifrey. Realising that the Master had the means to bring back the Time Lords, the Doctor took the gun and piloted the Vinvocci ship back towards the Naismith Manor, where he crashed through the manor's glass roof. However, he was unable to stop the Master from using the Star and the signal from the drums to create a link to Gallifrey, which allowed Rassilon and other Time Lords to appear. Rassilon undid the Master's conversion of the Human race, as Gallifrey appeared next to Earth. The Doctor then revealed why breaking the time lock and allowing the Time Lords to return was wrong. Opening the Time Lock would allow not just the Time Lords to return, but also all the horrors created in the War. As well as this, the Time Lords had devised a plan to destroy the time vortex and ascend to a state of pure consciousness. The Doctor, now recovered from his jump, took his gun and was torn between shooting the Master or Rassilon. Upon seeing a familiar face behind Rassilon, he targeted the White Point Star, severing the link, causing Gallifrey and the Time Lords to return to their proper time. Rassilon then tried to kill the Doctor, but he was saved by the Master, who used his powers to fight Rassilon and sacrificed himself as the Time Lords returned to the Time War.

The Doctor realised he had survived, but then he heard four knocks. Wilf was trapped inside a radiation control booth which was about to be flooded with radiation. Despite his own anger and Wilf's pleas to leave him, he released Wilf and took his place, receiving a fatal level of radiation. At first, however, it appeared as if the Doctor had survived this, too, but when a wound on his face suddenly healed itself, the Doctor realized that the regenerative process had started. Unlike previous occasions, however, the actual regeneration did not immediately occur, and the Doctor was able to not only return Wilf to his home, but spend an unknown length of time travelling through time and space revisiting his past companions, an act he referred to as his "reward". The Doctor visited Martha Jones and Mickey Smith, now freelance alien fighters and married, saving them from a Sontaran. He travelled to 13 Bannerman Road where he prevented Luke Smith from being run over by a car. He then travelled to a cantina on the planet Zog, where Captain Jack Harkness was drowning his sorrows in a drink. He passed a note to Jack reading, "His name is Alonso". Jack turned to see Midshipman Alonso Frame, (DW: Voyage of the Damned) and the Doctor departed as the two began flirting. The Doctor travelled to a bookstore where Verity Newman, a descendant of Joan Redfern, was signing copies of her book, A Journal of Impossible Things, the title of which came from the journal the Doctor wrote during his time as John Smith. (DW: (Human Nature) The Doctor had Verity sign his copy, and she realized he was the same Doctor. He then encountered Geoff Noble at some point before the man's death, and borrowed a pound from him. He then travelled to the future and used that pound to purchase a winning lottery ticket. He arrived at the wedding of Donna Noble and Shaun Temple, and asked Sylvia Noble and Wilf to give Donna the triple rollover-winning ticket as a wedding gift. The Doctor also visited Heather McCrimmon, a descendant of the Second Doctor's companion Jamie McCrimmon. (DWAM: Lucky Heather) Additionally, the Doctor visited all of his former companions from all of his previous incarnations, seeing how they got on. (SJA: Death of the Doctor) Finally, he travelled to the Powell Estate, on January 1st, 2005, where he observed Rose Tyler and her mother, Jackie Tyler, months before Rose first met him. Although he kept to the shadows, a sudden spasm of pain caught Rose's attention and the two exchanged New Year's greetings, with the Doctor telling Rose that she would have a "really great year" with tears in his eyes as he spoke.

After Rose departed, the pain of regeneration set in and the Doctor collapsed in the street. Ood Sigma then appeared and told him that while his song was ending, his story never would, and that the universe would sing for him. Reaching the TARDIS, he piloted it into orbit around Earth, stated "I don't want to go" and then regenerated for the tenth time. This time the energy released during the regeneration was enough to cause massive damage to the TARDIS. (DW: The End of Time)


 * For a list of Tenth Doctor stories in the order in which he experienced them, see Tenth Doctor - Timeline.

When Sarah Jane asked the eleventh incarnation if his previous incarnation had been okay and whether it hurt when he regenerated again, the Doctor remarked that "It always hurts." (SJA: Death of the Doctor)

When asked by the eleventh incarnation if Earth was defended, the Atraxi displayed holograms of past Doctors including the tenth incarnation which the eleventh Incarnation later walked through (DW: The Eleventh Hour)

Whilst experiencing the Doctor's past memories after the eleventh incarnation head butted him, Craig Owens saw an image of the tenth incarnation along with other Doctors, Monsters and Companions (DW : The Lodger)

The tenth incarnation's voice could later be heard by the eleventh incarnation's Ganger saying "Hello, I'm the Doctor" when he was struggling to cope with his Time Lord counterpart's past regeneraions (DW :  The Almost People)

Undated/Unchronicled events

 * The Doctor once commented that he, Rose Tyler, and an Arcturan had an interesting experience in a cellar. (BBCR: The Day of the Troll)
 * At one point, the Doctor and Rose Tyler visited a rocky, barren planet watching giant creatures, similar to manta rays in appearance, fly past. (DW: Army of Ghosts)
 * The Doctor tried to save Elton Pope's mother from an Elemental Shade from the Howling Halls, but was unsuccessful. (DW: Love & Monsters)
 * This occurred some point before the main events of Love & Monsters, as the Doctor recognised Elton as an adult.


 * An adventure involving bows and arrows was recalled by the Doctor during his encounter with Agatha Christie. (DW: The Unicorn and the Wasp)
 * This may refer to the unchronicled adventure with Martha Jones in Blink.


 * At one point the Doctor travelled with a green-skinned young alien named Majenta Pryce. (DWM: Thinktwice) Technically, however, the Doctor was considered Pryce's assistant, rather than the other way around. He also briefly reunited with on-again, off-again companion Maxwell Edison, who had previously shared adventures with the Doctor's fifth and eighth incarnations. (DWM: The Stockbridge Child)
 * The Doctor also shared adventures with Heather McCrimmon and Wolfgang "Wolfie" Ryter. (DWAM)
 * It is unclear whether the Doctor's companionship with River Song occurred during his tenth incarnation.


 * The Doctor saved a 13th century convent from a "demon from the sky" and was named the "sainted physician" by the locals. An image of the TARDIS was later incorporated into a stained glass window commemorating the event. (DW: The End of Time)
 * It is unclear, however, whether this event occurred to the Doctor's tenth incarnation or another.


 * There are several unchronicled periods in the Doctor's history during which some of his activities are unknown:
 * Between Donna Noble's initial invitation to join the TARDIS and his first meeting with Martha is unchronicled. (DW: The Runaway Bride, Smith and Jones)
 * During the interval between his first meeting with Donna Noble and the arrival of Martha Jones, the Doctor briefly travelled with an alien woman named Grayla. (IDW: The Whispering Gallery)
 * An unchronicled adventure with Martha Jones involving "four things and a lizard" and requiring the use of bows and arrows occurred in the modern day, during which the Doctor encountered Sally Sparrow and she handed him a package of information relating to events that had yet to occur to him. (DW: Blink)
 * At some point after his encounter with Sally Sparrow, the Doctor and Martha encountered the Weeping Angels and were transported without the TARDIS to 1969, where they spent an unknown length of time following the information provided by Sparrow. Their activities during this period have not been completely detailed. (DW: Blink)
 * After dropping Bayldon Copper off on Earth and before his reunion with Donna is unchronicled. (DW: Voyage of the Damned and Partners in Crime)
 * Adventures chronicled following the memory-wipe of Donna do not occur consecutively and thus any length of time may occur between them. (DW: Journey's End)
 * At some point after leaving Donna, the Doctor causes a change in a planet's timeline that results in a friend named Carla disappearing. Per Carla's request, the Doctor spent "years" searching for what became of Carla in the new timeline, eventually locating her. (DWA: The Haldenmor Fugue)
 * At some point after meeting Lady Christina, and after an adventure involving the Shadow Proclamation and an encounter with Mr. Finch and the Krillitanes. The Doctor rescinds his prohibition on not travelling with companions and invites Matthew Finnegan and Emily Winter, two inhabitants of 1920s Hollywood, to travel with him. (IDW: Fugitive, Tesseract) At some point during this period the Doctor was reunited briefly with Martha Jones and UNIT for an adventure. (IDW: Don't Step on the Grass)
 * The Doctor's discussion with Ood Sigma establishes an interval of indeterminate length between the Bowie Base One incident and the events leading to his regeneration, during which many events could have occurred. (DW: The End of Time)
 * The Doctor marries Queen Elizabeth I, then becomes her enemy. (DW: The Shakespeare Code)
 * It is not known how long the Doctor spent travelling to visit past companions before succumbing to radiation and regenerating. The 11th Doctor later told Jo Grant that he visited *all* of his previous companions, not just those specific to the 10th Doctor. (SJA: Death of the Doctor)

Donna's World

 * In the parallel timeline in which Donna Noble never met the Doctor, this incarnation of the Doctor was the last, as he was killed before he had a chance to regenerate as a result of his defeating the Empress of the Racnoss without being stopped. His former companion, Rose Tyler, along with the alternate timeline version of Donna, eventually restored the original timeline. (DW: Turn Left)

Personality
This incarnation was very cheerful, charismatic and enthusiastic, often at inappropriate times, even when in danger. (DW: Tooth and Claw) While previous incarnations intentionally flouted social conventions, the tenth incarnation was genuinely shocked when he was rude or uncouth. He frequently got into trouble because of his vast and loose sense of superiority. (DW: Midnight) He regularly provided his name as a threat, which only rarely worked, despite his apparent expectations. (DW: New Earth) This was mostly because so few species knew of his or the Time Lords' existence.

The tenth incarnation retained and even exceeded his last incarnation's capacity for righteous anger, which was especially shown when Rose was threatened or at risk. (DW: The Idiot's Lantern) When driven by anger or justice, he would act without hesitation to strike down those who opposed him, such as causing the downfall of Harriet Jones for, as he saw it, mass murder. (DW: The Christmas Invasion) There was an undeniable shadow cast over the jollity of him at these times, and a ruthless, bordering on arrogant personality seemed to take over, one that was almost eerie to behold.

While he had resolved much of the survivor's guilt felt previously, the Doctor had begun to feel his age. Beneath his youthful veneer and outward playfulness was a very old man who had seen many terrible things. He felt a deep loneliness and his keen sense of loss led him to empathize with those who had also suffered. Sarah Jane Smith tried to comfort him by saying that although he acted like a lonely man he had the biggest family in the world. She was referring to the many companions the Doctor had picked up on his travels. (DW Journey's End) This incarnation had a very forgiving nature, offering to help Dalek Caan even though he had committed genocide (DW Evolution of the Daleks). He also forgave the Master for all the atrocities he committed while he was ruling the Earth, which included turning his TARDIS into a paradox machine, torturing his companions for pleasure and turning him into an incredibly ancient man. (DW Last of the Time Lords). However when his patience reached its limit his enemies got no second chance which he stated himself shortly after defeating the leader of the Sycorax. (DW The Christmas Invasion). When he ran from the Family of Blood, he was showing them mercy, saving them from his rage. When they continued to hunt him, killing innocent people and separating him from his love interest, Joan Redfern, in the process, the Doctor lost his temper and gave each member of the Family of Blood an eternal punishment, fulfilling their wish for immortality in a twisted way. (DW: The Family of Blood) Donna would later link this mercy to his travelling with Martha, which the Doctor would agree on.

The Doctor had a very hard time accepting defeat or failure. When he was unable to save Astrid he kicked a teleport, screaming. (DW: Voyage of the Damned) Having seen so much destruction he felt driven to try to prevent it where possible. River Song thought that if he lost this trait, the universe would become a darker place. (DW: Forest of the Dead)

Upon their first meeting, Donna Noble noted that the reason the Doctor required so many companions was to keep him from succumbing to his darker urges. (DW: The Runaway Bride) After losing Donna to a meta-crisis, the Doctor chose to no longer take on companions and avoid getting his heart broken again. This time spent alone ultimately resulted in the Doctor succumbing to those darker urges and breaking the laws of time to satisfy his ego. (DW: The Waters of Mars)

The tenth incarnation engaged in romantic situations far more frequently than his predecessors. Having travelled with her since he was first shown in his ninth incarnation, the tenth Doctor fell in love with Rose Tyler and was heartbroken by her loss. (DW: Doomsday) However the Doctor never actually stated his feelings for Rose though he nearly did a few times. (DW: The Satan Pit, Doomsday). In the end it was the Meta-Crisis tenth Doctor that revealed the Doctor's feelings for Rose and since the Meta-Crisis Doctor was almost identical to the original Doctor, albeit a bit more violent and with some of Donna Noble's personality traits, as well as the fact that he possessed all of the original Doctor's memories, it is almost certain that the original Doctor felt the same way. Many others attempted to engage him romantically, including Madame de Pompadour, Joan Redfern, Martha Jones, Astrid Peth, River Song, and Christina de Souza. (DW: The Girl in the Fireplace, Human Nature/The Family of Blood, Voyage of the Damned, Silence in the Library/Forest of the Dead, Planet of the Dead) The Doctor reciprocated all of those except Martha, Christina and River, whose relationship was supposedly unknown to him.

This incarnation refused to take up a weapon against an enemy. While previous incarnations had, the tenth incarnation would not, repeatedly refusing even when offered one by UNIT while attacking the Sontarans. (DW: The Poison Sky) Davros even pointed out his refusal to take up a gun, but pointed out that he turned his companions into weapons. Eventually however the Doctor decided to take Wilfred Mott's pistol with him when he attempted to stop Rassilon and the Time Lords from destroying reality. (DW The End of Time)

This incarnation always attempted to find another way to solve a situation instead of violence if it was possible. He attempted to settle a dispute with the Sycorax leader without killing the leader, but was forced to when the leader betrayed his promise. Using the leader's defeat, he banished the Sycorax from Earth with the message that it was defended. He was extremely angered when Torchwood destroyed the ship afterwards. (DW: The Christmas Invasion) The Doctor also tried to help the Dalek survivors in New York to find a new world for themselves rather than fight to the death. He initially succeeded in convincing them until the Daleks turned against Dalek Sec. Even when only Dalek Caan was left, he tried to find a peaceful solution. (DW: Evolution of the Daleks) He also tried to get the Sontarans to leave peacefully after their plan was foiled, but they refused. Luke Rattigan killed them in place of the Doctor. (DW: The Poison Sky) Later, the Doctor tried to find a way to solve the Master Race crisis without killing the Master. When the Time Lords returned, he was forced to take a gun into the situation, being forced to choose between killing Rassilon or the Master. He found another way by using the gun to destroy the White Point Star diamond, breaking the link holding the Time Lords out of the time lock. (DW: The End of Time)

This incarnation had a great respect for Humanity, as well as a great desire to protect it, constantly noting their importance. Some of this may have come from the influence of his companions. Most notably however, was when Wilfred Mott said that Humanity must look like insects to the Doctor, but the Doctor responded that Humanity looked like giants to him. (DW: The End of Time)

Towards the end of his life, this incarnation was undeniably afraid of his predicted death, going on all sorts of adventures to circumvent or delay it. (DW: The End of Time)

Habits and Quirks
The Doctor made frequent reference to twentieth century pop culture, including the Ghostbusters theme, the song "Circle of Life" from The Lion King, and one of Kylie Minogue's songs, "Never Too Late". (DW: Army of Ghosts, The Christmas Invasion, The Idiot's Lantern) He had also read the Harry Potter books, noting that he cried after reading the seventh book (DW: The Shakespeare Code) Even though he knew so much of pop culture he did not understand certain remarks, such as being called a "science geek". (DW: The Lazarus Experiment) He was fond of rock and roll, trying to take Rose to see concerts by both Ian Dury and Elvis Presley. (DW: Tooth and Claw, The Idiot's Lantern)

He often remarked that exotic technology or life is "beautiful" or "brilliant" and was genuinely enthralled by such discoveries, sometimes to the extent that he placed himself or his companions in danger. When this incarnation was faced with an occurrence that dumbfounded him he would repeatedly say "What?", increasing the expression on his face each time. While attempting to explain something he would often interrupt himself with a "Well..." and further elaborate what it was he was talking about (DW: Blink, et al) The Doctor was also fond of the phrase "I'm sorry, I'm so sorry", mainly talking to persons he knows are about to die and whom he cannot save. Other favoured phrases were "Allons-y!" and "Molto bene." Like his seventh incarnation, he also often responded "I'm always all right" even when all evidence pointed to the contrary.

He also regained an ability from his Fifth Incarnation, which was being able to determine the properties of an object by simply tasting them. (DW: The Christmas Invasion, The Idiot's Lantern, Tooth and Claw, Utopia, The Fires of Pompeii, The Sontaran Stratagem, The Unicorn and the Wasp)

This incarnation of the Doctor spoke in alien languages very often, using it to taunt the Sycorax Leader and communicate with the Tritovores and the Judoon.

Until they left his life, he continued his previous incarnation's habit of mildly mocking both Mickey and Jackie, though generally in a more obviously playful fashion.

The tenth incarnation of the Doctor also has a fondness for bananas like his predecessor. (DW: The Girl in the Fireplace) The tenth incarnation also had a deep dislike for pears. (NSA: The Taking of Chelsea 426) The Doctor has a stated fondness for "little shops", the gift stores usually found in hospitals and other public places.

This incarnation of the Doctor relied heavily upon his sonic screwdriver, pushing it to limits not seen in previous incarnations and even chiding his fifth incarnation for going "hands free". (DW: Time Crash) He also continued to heavily use the psychic paper. (DW New Earth et al) Like previous selves, he appeared to have the ability to carry a large and diverse number of objects in his pockets, stating once that they were bigger on the inside. (DW: The Runaway Bride)

He also revived the occasional use of a stethoscope, like his second incarnation in mostly non-medical situations, such as the diagnosis of electronic or mechanical fault. (DW: Fury from the Deep, The Horns of Nimon, Rise of the Cybermen, The Stolen Earth) He used his hammer many times during this incarnation, using it to knock out Sontarans and even pilot the TARDIS.

He had taken to carrying a GSM mobile phone with him. The number could be used to contact him anywhere in space and time. (DW: The Sontaran Stratagem, The Stolen Earth) Like his previous incarnation did with Rose Tyler's "superphone", this incarnation also upgraded the mobile phones of his later companions in order to facilitate communication with their families and with the Doctor. Both Martha Jones and Donna Noble's phones were modified and, like Rose's mother, their close relatives were able to communicate through time and space as a result. (DW: The Stolen Earth) The phone he carried was Martha Jones' superphone, given to him by her so she could contact him if need be. It could be called using any standard phone. (DW: The Sontaran Stratagem, The Stolen Earth)

He also followed the trend of his immediate predecessors in displaying increasing skill for using the TARDIS, on several occasions even using it in the form of a standard spaceship rather than simply dematerialising it every time. (DW: The Runaway Bride, Partners in Crime) He was told by a future companion, River Song, that he would one day be able to command the TARDIS by a snap of his fingers. Initially, he believed this to be nonsense, but later found that he did possess such abilities. (DW: Forest of the Dead)

The Doctor often did math calculations in his head very fast. This included making an estimate, waiting for those around him to respond, then giving a very exact answer. (DW: Voyage of the Damned)

Appearance
The tenth Doctor was a very handsome man with a tall, thin build, dark brown hair, pale skin and twinkling dark brown eyes.

Grooming and hair
The tenth incarnation was happy to have sideburns and to have more hair than his previous incarnation, whose hair was very close-cut. (DW: Children in Need Special) Though he initially seemed disappointed at not being ginger, he would come to take great pride in his dark brown hair, wearing it in various ways throughout his adventures. He would wear it un-styled, (DW: The Christmas Invasion) in a fifties-style quiff, (DW: The Idiot's Lantern) or flattened forwards. (DW: The Runaway Bride)

Clothes
For the early minutes of his life, the Doctor continued to wear the clothes his previous incarnation had on at the time of his regeneration. After arriving in London and collapsing, he was placed in a set of pajamas and a dressing gown, which he kept until the end of his first adventure, when he chose a new outfit. (DW: The Christmas Invasion)

This incarnation had several variations of dress. He had two main suits, a dark brown suit with blue pinstripes and a blue suit with red pinstripes. On rare occasions, he would don a tuxedo. (DW: Rise of the Cybermen, The Age of Steel, The Lazarus Experiment, Voyage of the Damned)

Under his suits he usually wore a shirt and a tie, or wore an open-necked shirt with a t-shirt underneath. He had a red-hued t-shirt, a brown t-shirt or a purple t-shirt. Both brown and blue suits were often accompanied by a light brown overcoat, which the Doctor claimed was given to him by Janis Joplin. (DW: Gridlock)

The Doctor appeared to have more than one suit of each design. The Meta-Crisis Doctor wore a blue suit after his creation, and was wearing it when the walls of the universe sealed him in a parallel world. (DW: Journey's End) Nevertheless, the Doctor subsequently wore a blue suit on several occasions, implying he had more than one. (DW: Music of the Spheres, SJA: The Wedding of Sarah Jane Smith, DW: The Waters of Mars)

His footwear choices were trainers, more specifically, Converse All Stars. He varied the colours from cream, to go with his brown suit, black, for wearing with his tuxedo and on a few occasion with his brown suit, or burgundy, to go with the blue suit. Another part of the Doctor's attire was a pair of dark tortoise-shell rectangular frame glasses, which he called "brainy specs". Although he had been seen to put them on on numerous occasions, he once confessed that he didn't need them, and simply used them because they made him look more clever. (DW: Time Crash)

His favourite variation of dress seemed to be his brown suit with blue pinstripes, a light blue shirt, a tie and cream Converse All Stars.

Lifespan
The Doctor's actual age is a matter of some debate. Assuming the Doctor's stated age of 900 around the start of this incarnation was correct, it would appear he lived for slightly less than 7 years, given his stated age of 906 just prior to his regeneration. (DW: The End of Time) His next incarnation would state his age as 907 early in his adventures. (DW: Flesh and Stone) There are, however, some discrepancies as there are some accounts that suggest his stated tally may not be correct. (DW: The Infinite Quest)
 * See separate article.

Costuming
David Tennant described his costume "geek chic." According to an interview on Parkinson, Tennant and Russell T. Davies got the idea for the tenth incarnation's costume from an outfit Jamie Oliver had worn on Parkinson just after Tennant had taken the role of the Doctor.

According to costume designer Louise Page, there were only four sets of the brown suit, in existence as they were pieced together from many copies of a pin-striped pair of trousers that Tennant picked out during the initial costuming process. His overcoat was made from sofa covering and there was one version that had five inches from the bottom cut off then sewn back on, as Davies and Phil Collinson had different ideas about how long it should be.

Regeneration
Russell T. Davies had said in an interview that the tenth incarnation's regeneration had been filmed and was planned out in mind since David Tennant was signed on for the role; Davies also heavily implied that had Tennant not played the tenth incarnation, there would have been a different regeneration.