Leela

Leela was a warrior of the savage Sevateem, a tribe of regressed humans. She joined the Fourth Doctor on his travels and with him fight for good causes. She knew little of technology and was continually amazed by her surroundings and tasks she faced. She never lost her primitive nature and remained quick to arms throughout her time with the Doctor.

She only left the Doctor after she fell for Andred, another Time Lord, and went to live on Gallifrey with him. Her challenges did not end there and she continued to aid the Time Lords.

Meeting with the Doctor
Leela, the daughter of Sole and friend to Tomas, was one of the Sevateem (the name originated as a corruption of "survey team") descended from the Mordee expedition. For weapons, Leela favored a knife and janis thorns, which caused paralysis and death.

Leela profaned the Sevateem's god, Xoanon. Her father died undertaking the ritual test of the Horda on her behalf. She faced exile when she met the Doctor, who resembled the Sevateem's mythic figure, the Evil One. He had earlier visited Leela's world, repaired the Mordee expedition's computer, Xoanon, and forgot to remove his own personality from it. The conflict between Xoanon and the Doctor's personality drove Xoanon mad,splitting his personality in two. It conducted a long term eugenics experiment that culminated in two tribes: the Sevateem and their enemies, the Tesh. The Doctor restored Xoanon's sanity. As he prepared to leave the planet, Leela intercepted the Doctor and asked to travel with him. He refused, but Leela darted into the TARDIS and they set off together after Leela accidentally triggered the TARDIS' dematerialisation. (DW: The Face of Evil)

Travels
Leela was a primitive, but she was very smart. She translated advanced ideas into terms she could understand. Despite the Doctor's efforts to "civilise" and educate her, Leela kept her savage ways. She usually dressed in animal skins, armed with her knife and Janis thorns, which she did not hesitate to us when threatened, despite the Doctor's disapproval. Alongside the Doctor, Leela fought Taren Capel (DW: The Robots of Death) and, in Victorian London, Magnus Greel, when the Doctor had attempted to show Leela how her ancestors had lived. (DW: The Talons of Weng-Chiang) They picked up K9 from Professor Marius. Leela killed a number of the Titan Base relief crew who were infected. (DW: The Invisible Enemy) On Pluto, Leela was rescued from the steamer moments from death. She took part in the Citizens' Revolution, that overthrew the Company. (DW: The Sun Makers)

When Leela and the Doctor visited the home of one of the Doctor's former companions, Joshua Douglas, and his family, Leela met the imprisoned emperor of the Z'nai, whom the Doctor had contained long before in the hope of finding an antidote for the plague which Douglas had once released to destroy his people. Douglas' daughter freed the emperor, sparking a new resurgence of the Z'nai empire. For some reason which has not yet been revealed, Leela became the virus' vector, infecting the Z'nai with it. Leela wiped out the Z'nai, all except for the emperor, whom the Doctor imprisoned once again. (CC: The Catalyst)

Life on Gallifrey
The Doctor, seemingly power-mad, returned to Gallifrey and applied successfully to become Lord President of the High Council of Time Lords Banished from the Capitol, Leela joined the Outsiders, outcast Gallifreyans lead by Nesbin. She helped to repel an invading force of Sontarans. She also fell in love with Andred of the Chancellory Guard, and stayed on Gallifrey with K9. The Doctor had a second K9 to take along with him. (DW: The Invasion of Time)

She would spend the next decades in the Capitol. Andred and Leela conceived a child, the first born on Gallifrey for millennia. (Pythia had long ago made the Gallifreyans a sterile race.) (NA: Lungbarrow) Later, Andred vanished and Leela served as bodyguard and confidante to Lady President Romana - another former companion of the Doctor. (BFG: Weapon of Choice) Leela would bedrawn into Time Lord politics and conspiracies while working on Presidential missions with Celestial Intervention Agency operatives Torvald and Coordinator Narvin. (BFG: Square One, A Blind Eye) Leela discovered that Torvald had caused Andred's death, but it was later revealed that Torvald was in fact a regenerated Andred. (BFG: A Blind Eye) Leela had not forgiven Andred for his deceit when he died soon afterwards. During the troubled time that followed, Leela's most trusted friend, K9, was destroyed in an explosion aimed at the Off-world students of the Time Lord Academy. Bitter at the loss of her last link with the Doctor, Leela refused a replacement. (BFG: Imperiatrix) In the Time Lord civil war, Leela fought on the side of Romana and was temporarily blinded by a bomb. (BFG: Fractures)

Life after Gallifrey
Her sight at last restored, Leela survived the destruction of Gallifrey in the Last Great Time War, she ended up a prisoner of the Z'Nai, who had returned to power. While Leela lived on Gallifrey, the Time Lords allowed her to retain her youth for a greatly extended period of time. This was no longer so. As the Z'nai tortured Leela for information about Gallifrey and the Time Lords, she physically aged one year for each natural day.

The Z'nai had abandoned their ancient custom of leaving their chests bare. Just before the Z'nai interrogating her was about to kill her, she gave him a choice - stop the killing or be killed. He laughed, and she infected him with the plague that had wiped out the Z'nai originally. The entire race died, leaving Leela and the other prisoners at first joyful, then terrified as they realized that they were trapped and abandoned. Leela remained bound, without the strength to free herself, reminiscing about her days with the Doctor as she waited to die. (CC: The Catalyst)

Other information

 * When a Rutan ship exploded above Fang Rock, pigmentation dispersal caused Leela's eye colour to permanently change from brown to blue. (DW: Horror of Fang Rock)
 * Leela wrote with her left hand and threw knives and did other actions with her right, suggesting some degree of ambidexterity (DW: The Invisible Enemy).
 * The Doctor commented on the fact that Leela's child would be half-Gallifreyan and half-human. He told Leela to name the child after him. (NA: Lungbarrow) This raises the possibility that Leela's child actually became the Other (although it is not known that the Other was half-human), making Leela, in a way, the Doctor's mother.

Creation of the character
The character of Leela was first conceived by producer Philip Hinchcliffe and script editor Robert Holmes. They wanted a companion in the mould of Eliza Doolittle in George Bernard Shaw's play Pygmalion: a bright but unsophisticated primitive who would learn from the Doctor. Writer Chris Boucher had submitted a story proposal entitled "The Mentor Conspiracy" which featured a character named Leela which fit Hinchcliffe and Holmes's ideas.

Although The Mentor Conspiracy was not produced, Boucher reused the character of Leela for The Day God Went Mad (later renamed The Face of Evil), seeing her as a mixture of Emma Peel from The Avengers and Leila Khaled. Boucher was asked to write two endings to the story, one where Leela left with the Doctor and one where she stayed behind. The decision to have Leela become a companion was made soon after.

Initially, Leela was to have only appeared in three stories. It was later decided that she would stay for all of Season 15. One consequence of this decision was a plot contrivance being added to Horror of Fang Rock to allow the character's eye colour to change, so that actress Louise Jameson would no longer have to wear uncomfortable coloured contact lenses.

Leela ranks as arguably one of the most violent companions, and used deadly force against other humanoids (often to the disgust of the Doctor as in DW: The Invisible Enemy, but occasionally not as in DW: Underworld), or threatening same. Although other companions killed (Romana I shot a guard in DW: The Pirate Planet), and others have killed in spin-off productions (most notably Jack Harkness in Torchwood), and Ace raked up body counts in the novels, Leela remains the only TV companion to be shown killing on a frequent basis.