Second Doctor

Biography
The Second Doctor began his life as the First Doctor's body finally wore out during an encounter with the Cybermen at the Snowcap Base in 1986, forcing him to regenerate. Almost immediately after this new life began, the Doctor found himself thrown into a battle with his old enemies, the Daleks, at the Earth colony on Vulcan. Owing to the non-sequential appearances of the Doctor in their own history, these Daleks already recognized this Doctor from what for them was a previous encounter.

While the First Doctor's companions, with the possible exception of Susan, had been from the 20th century or the future, this Doctor acquired two companions from Earth's past, namely Jamie McCrimmon, from the year 1745, and Victoria Waterfield, from 1866. Only Ben and Polly, whom the Doctor had "inherited" from his predecessor, and his last companion, Zoe Heriot, were from the periods in which the First Doctor was likely to meet new assistants.

It was in this incarnation that the Doctor had his first known encounters with the Yeti and the Ice Warriors. Most authorities agree that his first battle with the Time Lord criminal known as the Master also occured during this period. The Doctor also continued to have battles with the Daleks, at one point fomenting a civil war among the Daleks which he believed, or at least hoped, was their final end. He especially had continued battles with the Cybermen. Perhaps most importantly, in battles with the Great Intelligence and the Cybermen the Doctor had his first meetings with Alistair Gordon Lethbridge-Stewart, who would play significant roles in some of the Doctor's greatest adventures.

Finally, after untold years of eluding capture, the Doctor was forced to betray his location to the Time Lords in order to enlist their help in returning the many soldiers kidnapped from various periods of Earth history by the War Lords. The Second Doctor was captured and placed on trial for violating the cardinal rule of the Time Lords against interference in the affairs of other worlds. Sentenced to exile to 20th century Earth, the Doctor was forced to undergo another regeneration.

From some point prior to this moment, the Second Doctor was recruited by the Time Lords to help the Third Doctor in his battle with Omega. There exists some evidence that, just as the Third Doctor was rewarded by the Time Lords by having his exile rescinded, the Second may have been shunted into an alternate timeline, or had his exile delayed, on condition that he work as the Time Lords' agent when needed.

Personality
The Second Doctor was a complete change of pace from his predecessor. Whimsical, buffoonish, witty. The Doctor was no longer a grandfather figure, but rather more of a favourite uncle. Indeed, the slow transition of the First Doctor from a reluctant travelling companion to a more kindly compatriot was completed here, as the Second Doctor very much enjoyed embroiling himself in adventures with his assistants. Despite this Doctor's almost childlike recklessness, it was always clear to his allies that a keen, deliberate intellect lurked behind every action. Although the Second Doctor frequently gave the impression that he never knew what he was doing, this was simply an affectation: an act put on to fool those who would underestimate him.

Habits and Quirks
The Second Doctor dressed similarly to the First Doctor, though in far less natty fashion, the pants now clownishly large and the cravat replaced with a bow tie. He abandoned the blue signet ring as it no longer fit him. In his first adventure on Vulcan he possessed a tall stovepipe hat, never seen subsequently. He also possessed a recorder which he played to concentrate or while under stress.

On Vulcan, Scotland ("The Highlanders") and Atlantis ("The Underwater Menace"), he posed as or disguised himself as other people, sometimes positively relishing the chance. Less willingly, he also impersonated Salamander, the Second Doctor's physical double.

The Second Doctor introduced several qualities later picked up upon by future incarnations. The Doctor first showed interest in Tibetan Buddhism to us in this incarnation ("The Web of Fear"). He also first revealed to us and his companions the Five Hundred Year Diary ("The Power of the Daleks"), his sonic screwdriver ("Fury from the Deep") and the alias Doctor John Smith ("The Wheel in Space"), all of which he would return to in later incarnations. His ability to pull almost any object from his pockets originated with him, also.

Mysteries and Discrepancies

 * The Second Doctor showed a certain familarity with the Cybermen tombs on Telos ("The Tomb of the Cybermen"). Additionally, the Cyber-Planner recognized the Second Doctor and Jamie from Planet Fourteen not shown on screen ("The Invasion").


 * Evidence suggests the Second Doctor's life continued some time after his trial by the Time Lords.