Biography

New life

This incarnation's life began began his life when his First Doctor] finally wore out during an encounter with the Cybermen and he regenerated. (DW: The Tenth Planet).

The Doctor found himself suspected as an imposter by his companion Ben Jackson and thrown thrown into a battle with his old enemies, the Daleks, at the Earth colony on the planet Vulcan. The fact that the Daleks recognized Ben as their enemyconvinced him of the Doctor's credentials and by the end of this adventure, the Doctor had won over the trust of Ben and Polly. (DW: Evil of the Daleks)

New companions

Shortly, the trio met Jamie McCrimmon, in 1745 Scotland and let him come along on their travels (DW: The Highlanders.

Together, on Earth's Moon, they would fight a new, more machine-like form of Cyberman. (DW: The Moonbase).

Ben and Polly decided to stop off together on 1966 (DW: The Faceless Ones). The Doctor found themselves transported abducted back to 1867. Two 19th century Human scientists, Edward Waterfield and Theodore Maxtible, trying to isolate the Human Factor. Jamie and the Doctor befriended Waterfield's daughter, Victoria. Waterfield now having died and the introduction of the Human Factor having instigated a war on Skaro, the Doctor and Jamie left with Victoria. The Doctor believed at the time that the Daleks had truly destroyed each other, forever. (DW: The Evil of the Daleks)

Cybermen, Yeti and Ice Warriors

With Jamie and Victoria alongside him, the Doctor forced back the Cybermen back to their ice tombs on Telos and first encoutnered the Cybermats (DW: Tomb of the Cybermen. On Earth had their first known encounters with the Yeti and the Great Intelligence (DW: The Abominable Snowmen') and the Ice Warriors (DW: The Ice Warriors).

During a second battle with the Great Intelligence and the Yeti, the Doctor met for the first time, then-Colonel Alistair Gordon Lethbridge-Stewart (DW: The Web of Fear).

:Lethbridge-Stewart would later found UNIT and play a significant roles in some of the Doctor's greatest adventures.

Menoptera, Veltrochni and Koschei

The TARDIS landed once more on Vortis (MA: Twilight of the Gods). On Doctor met, once again, Near Darkheart, they encountered the war-llike Veltrochni and Koschei, an close friend from Gallifrey, now sent by the Time Lords to retrieve him. (MA: The Dark Path).

Craving peace and quiet, Victoria left the TARDIS crew to live with the Harris family. (DW: Fury of the Deep).

Cybermen, Quarks and Ice Warriors

The Doctor and Jamie discovered a Cyberman plot involving a space station and picked up one of the space station's crew, Zoe Herriot. To make sure that she really wanted to come with them, the Doctor showed her a mental projection of his last adventure with the Daleks in the year 1966 (DW: The Wheel in Space)

On the plnaet Dulkis, the Doctor, Zoe and Jamie first fought the Quarks. (DW: The Dominators). Shortly after an adventure in the Land of Fiction (DW: The Mind Robber) the travelers landed on Earth where learned Lethbridge-Stewart, now a Brigadier, headed a new alien defense organization named UNIT. Alongside UNIT, they defeated Tobias Vaughan and the Cybermen (DW: The Invasion)

Late they once more battled the Ice Warriors. (DW: The Seeds of Death).

The trial and its aftermath

The Doctor discovered a former friend, Magnus, now calling himself the War Chief, who had given spacetime vessel technology to the War Lords, a race planning to use Human soldiers as an army to conquer the galaxy. The Doctor was forced to betray his location to the Time Lords in order to returning the many soldiers kidnapped from various periods of Earth history. (DW: The War Games)

The Doctor was captured and placed on trial for violating the cardinal rule of the Time Lords, never to interfere. His sentence would consist of exile on Earth in the 20th century and a forced regeneration. (DW: The War Games).

The Celestial Intervention Agency had stepped in, secretly, to intercede and prevent the Time Lords from executing the Doctor. (DW: The Deadly Assasin). Reluctantlly, the Doctor then worked for them. (DW: The Two Doctors, PDA: World Game)

At an unknown later time, the Doctor did regenerate and the Doctor's exile commenced.

Characteristics

Appearance

The Doctor dressed similarly to his earlier self, 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. (DW: The Power of the Daleks). He had longish, rumpled hair and blue eyes. In later years, his dark hair began to gray. (DW: The Two Doctors)

Psychological profile

Personality

The Second Doctor was a complete change of pace from his predecessor; whimsical, buffoonish and 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

While in the Land of Fiction he wore it again and gave it to Bernice Summerfield, who needed it to complete the second Key to Time. (DWM: Time and Tima Again)

He also possessed a recorder which he played to concentrate or while under stress. (DW: The Power of the Daleks onwards.)

On Vulcan he In Scotland, he posed as a German physican., calling himself Doctor von Wer (DW: The Highlanders]]) and in Atlantis he dressed as a strange gypsy-like musican (DW: The Underwater Menace). In most of these instances, he seemed as much motivated by the fun of doing it as much as for any practical purpose.

The alias Doctor von Wer translates, roughly, in English to "Doctor Who".

Taking events more seriously,, he impersonated the murdered Earth Examiner (DW: The Power of the Daleks). Agains his will, he also impersonated Salamander, the Doctor's physical double. (DW: The Enemy of the World). On the Wheel in Space, he adopted for the fist time the alias of Dr. John Smith. (DW: The Wheel in Space).

This Doctor introduced several qualities later picked up upon by future incarnations. The Doctor first showed an interest in Tibetan Buddhism in this incarnation (DW: The Abominable Snomwen). He also first revealed to his companions the Five Hundred Year Diary (DW: The Power of the Daleks), and his sonic screwdriver (DW: Fury from the Deep). He had the ability to pull almost anything out of his pockets. (DW: The Five Doctors)

Mysteries and Discrepancies

How did the Daleks on Vulcan recognize the Doctor?

The Daleks could have come from further ahead in the Doctor's personal timestream. Otherwise, they may simly have deduced his identity without having encountered this incarnation before.

At what time in his life did the Doctor fight Omega alongside his past and future selves?

We only know this event happened, for him, sometime after he fought the Cybermen alongside UNIT.

The Doctor showed a certain familarity with the Cybermen tombs on Telos (DW: The Tomb of the Cybermen).

When did Jamie finally return home and under what circumstances?

When did this incarnation really regenerate?

Unrecorded adventures

Probably the Doctor and Jamie had least one other adventure together.

Not exactly an unrecorded adventure, a future incarnation of the Doctor, along with an older Jamie fought the Cybermen on Marinus, (DWM: The World Shapers). Later (from the Cyber-Planner's point of view), the Cyber-Planner would refer to this. (DW: The Invasion)

Strangely, the Doctor later recalled the Cyber-Planner saying this (DWM: The World Shapers), even though he could not possibly have heard.

Key Life Events

The Doctor regenerates. (DW: The Tenth Planet, The Power of the Daleks)
The Doctor meets Jamie McCrimmon (DW: The Highlanders)
The Doctor meets then-Colonel Alistair Gordon Lethbridge-Stewart. (DW: The Web of Fear)
The Doctor discovers that Lethbridge-Stewart, now a brigadider, in coommand of the newly-formed UNIT. (DW: The Invasion)
As a last resort, the Doctor brings in the Time Lords to resolve a situation he thinks he cannot handle on his own. The Time Lords return Jamie and Zoe him on trial for interfering in the destiny of the universe. (DW: The War Games)
The Celestial Intervention Agency uses the Doctor as an agent and sends him on a mission with Lady Serena. (PDA: World Game)
Still working for the CIA and with Jamie once more by his side, the Doctor meets his sixth incarnation. (DW: The Two Doctors)
The Doctor regenerates.

Though we know what happens afterwards and why, details of the actual regeneration remains vague.