Fourth Doctor

Indepedence
Having regenerated, the Fourth Doctor seemed to be in a hurry to leave Earth, but was eventually persuaded to stay and help Brigadier Lethbridge-Stewart deal with Think Tank and their K1 robot. The Fourth Doctor took Sarah Jane Smith and Harry Sullivan to travel with him in the TARDIS. (DW: Robot)

In the midst of another adventure, a Time Lord appeared to the Doctor and offered him a mission, to intervene in the creation of the Daleks, either to prevent it to induce the Daleks to develop into less dangerous creatures. (DW: Genesis of the Daleks)


 * This set into motion a series of events that would eventually lead to open war between Daleks and Time Lords the destruction of Gallifrey.

Upon his return to Earth and the defeat of the Zygons, Harry decided to remain. (DW: Terror of the Zygons)


 * ''The Doctor had begun, even more so with this regeneration, to break his ties with Earth. We do not know when, if ever, he formally left his position as UNIT's unpaid scientific advisor or if he had not done so already.

Return to Gallifrey
After many adventures together, the Doctor received a telepathic summons from Gallifrey and returned Sarah to Earth (DW: The Hand of Fear), mistakenly returned her not to her home in South Croydon but to Aberdeen. (DW: School Reunion).

On Gallifrey, the Doctor defeated the Master and renewed his acquaintance with his former teacher Borusa. He also re-experienced, to his disgust, the decadence of Time Lord civilization. (DW: The Deadly Assassin).


 * The Doctor travelled for an unknown period of time alone.

New friends
Visiting a nameless jungle world, he made the acquaintance of Leela of the Sevateem (DW:The Face of Evil)

Lord President of Gallifrey
Returning once more to Gallifrey and, posing as vainglorious and power-mad, sought and attained the office for Lord President as part of a scheme to save his homeworld from an invasion force of two separate enemies, the Vardans and the Sontaran]s]. Leela decided to remain on Gallifrey with [[Andred, a Gallifreyan in the Chancellory Guard and K-9. However, the Doctor left the Capitol with a duplicate K-9, Mark II, in a crate (DW: The Invasion of Time).


 * The Doctor and K-9 Mark II spent an indeterminate period of time together.

Quest for the Key to Time
The White Guardian summoned the Doctor to initiate a quest to locate and assemble the segments of the Key to Time. For this purpose, the White Guardian introduced him to a new companion, Romana (DW: The Ribos Operation).The Doctor and Romana located, assembled and dissasembled the Key, and to escape the wrath of the White Guardian's opposite, the Black Guardian, the Doctor installed a randomizer in the TARDIS console (DW]: [[The Armageddon Factor).

E-Space
Struggling with the Master, he fell off the Pharos Project radio telescope down the ground hundreds of feet below. The mysterious entity known as the Watcher, which had been tracked him through time and space, then merged with him and he regenerated.



=Characteristics=

Appearance
In stark contrast to the elegant, refined figure of his third incarnation, the Doctor was an unkempt, awkward-looking figure, dressed in battered clothing and an impossibly long multi-coloured scarf, knit for him by Madame Nostradamus. (DW: Robot).

Personality
This incarnation was most definitely not Human, and stood apart from others, even most of his own people. (DW: The Deadly Assasin, The Invasion of Time)

When Sarah upbraided him over his callousness at the sight of a man killed by the animate corpse of his own brother, the Doctor reminded her of the larger issue of stopping Sutekh. (DW: Pyramids of Mars). His mind five leaps ahead of anyone, including himself, only Romana seemed able to keep up with the Doctor's trains of thought. He delighted in keeping both friends and foes alike off guard with oddball humour and curious pranks, as in his second incarnation.

He could judge character keenly almost instantly whether knowing who to trust or seeing through Unstoffe's faux guilesssness (DW: The Ribos Operation), Out of all the Doctor's selves, this incarnation had perhaps the most consistently anti-authoritarian attitude, having little tolerance for religious dogma (DW: The Brain of Morbius, Underworld) or nationalism (DW: Robot, The Armageddon Factor). The Doctor often played the fool to lull his opponents, such a Count Scarlioni, into underestimating him. (Though it did not work in that case.) But he was also a very intense, brooding individual, at times displaying a seriousness and fury belying his usually whimsical attitude, such as, when telling the scientist Sorenson that he must put right what he done wrong, even if he must sacrifice his life to do so (DW: Planet of Evil).

Habits and Quirks
Souvenirs from many different worlds littered his pockets. (DW: Robot, Genesis of the Daleks). He would sometimes relaz by playing with a yo-yo and liked to drink ginger beer (DW: The Android Invasion).

He would often have with him and offer jelly babies as a greeting. In his later life he developed a great reliance for tinkering about in the TARDIS. He relied upon his sonic screwdriver at least as much as in his previous incarnation.

Mysteries and Discrepancies

 * The Fourth Doctor visited Leela's home planet, presumbably alone, encountered the supercomputer Xoanaon and inadvertantly installed in him a program copied from his own personality (DW: The Face of Evil). We do not know at what time in the Fourth Doctor's life this event occured or the reason why, later, he would fail to remember his adventure. One theory for the amnesia explains that this adventure as happening very early in his life, when he still suffered from post-regenerative trauma.

=Key Life Events=


 * The Doctor regenerates. (DW: Planet of the Spiders, Robot)


 * On Skaro, the Doctor attempts to prevent the creation of the Daleks. (DW: Genesis of the Daleks).


 * Sarah Jane Smith leaves (DW: The Hand of Fear) and the Doctor returns to Gallfrey, where he must defeat the Master (DW: The Deadly Assasin).


 * The Doctor meets K-9 Mark I, who joins the TARDIS crew. (DW: The Invisible Enemy)