Second Doctor

Though outwardly warm, bumbling and clownish, the Second Doctor also had a darker, more cunning aspect to his personality — one which he usually kept hidden in order to carry out his plans. Regenerating when his first incarnation gave in to old age and fatigue following his fight with the Cybermen, this new incarnation was the product of the Doctor's first regeneration.

He travelled with a number of companions, starting with his previous incarnation's last companions, Ben Jackson and Polly Wright, before adding Highland Scot Jamie McCrimmon to the TARDIS. After a while, Ben and Polly left, to be replaced by Victoria Waterfield, a woman orphaned by the Daleks. In time, she too left, and the Doctor made a new friend in the mentally gifted Zoe Heriot. At some point, he also travelled with his grandchildren, John and Gillian.

His adventures came to an end when he called on his people for help with the evil machinations of the War Lords. Though the Time Lords did indeed render assistance, they also condemned him to exile on Earth and a new body for breaking their non-interference policy many times over. The Celestial Intervention Agency was able to stay the execution of this sentence for a while in exchange for the Doctor providing his services to them. During these later years of his life, the Second Doctor variously carried out covert operations for the CIA and lived in luxury and fame in the heart of 1960s London. Eventually, though, Time Lord justice reasserted itself, and the Doctor was indeed forced to regenerate into his third body.

Alternate timelines
In an alternate timeline created by the Discordia, the Doctor had a passionate romantic relationship with River Song that began in his first incarnation, having married her by his fourth incarnation. In one of their outings, River convinced the Second Doctor to dress as Ramón Salamander for "fun". (AUDIO: Someone I Once Knew)

When the Cybermen allied with Rassilon to take over history, they manipulated the encounter at the Moonbase leading to the Second Doctor being partially cyber-converted. (COMIC: Prologue: The Second Doctor)

While aiding an archaeological team on Telos, (TV: The Tomb of the Cybermen) a Cyberman time squad attacked the Doctor. This would have killed him if their Controller didn't order them to stop at the risk of erasing their future invasion of Krelos due to the unwitting role of the Fourth Doctor in that plan. The Second Doctor then witnessed a Krelos robot drone decontaminate Jamie before time was reset and this interlude didn't happen. (AUDIO: Return to Telos)

In an alternate version of the London Event, the Doctor was killed by Colonel Spencer Pemberton in the London Underground. (PROSE: Legacies)

Behind the scenes

 * Rupert Davies, Valentine Dyall, Michael Hordern and Brian Blessed were all approached for the role of the Second Doctor. All declined, as they didn't want to commit to a long-running series.
 * Matt Smith, in preparation for his role as the Eleventh Doctor, watched the Troughton serial The Tomb of the Cybermen, and fell in love with it. He describes Troughton as "rather wonderful" and as being his favourite Doctor. Smith's costume and mannerisms are reminiscent of Troughton's.
 * Almost half of the episodes from the Second Doctor's era have been lost, leaving only seven of Patrick Troughton's 21 TV stories still fully intact (excluding his appearances in multi-Doctor specials). Five further incomplete stories have been released commercially, with specially-created material to bridge the missing episodes. Surviving "orphan" episodes and footage have been released on the Lost in Time DVD collection.
 * The Second Doctor was the first incarnation to directly work with four of his other selves on television, though that turned out to be a number also attained by the Fifth Doctor by virtue of Time Crash. If one includes a story this wiki generally doesn't — Dimensions in Time — then it could be said that the Third and Sixth Doctors were on the "four-timer" list, as well. However, there was no actual "interaction" between Doctors in Dimensions.
 * Until Time Crash, the Second Doctor was the only incarnation to appear in all televised multi-Doctor stories. As of 2013, Troughton holds the record for working with the highest number of other incarnations, having directly interacted with four other Doctors: the First, Third, Fifth, and Sixth Doctors. Taking into account all performed media, however, the record-holder is Peter Davison. His appearances on audio with the Sixth, Seventh, and Eighth Doctors add to his totals from The Five Doctors and Time Crash, to give a grand total of eight other Doctors.
 * The Second Doctor was the first incarnation to have his face integrated into the Doctor Who title sequence, beginning with The Macra Terror.
 * The Second Doctor is the only incarnation who was forced to regenerate, though the regeneration isn't seen in The War Games, and was confirmed he didn't regenerate until The Night Walkers, the only story to actually show the Second Doctor's regeneration properly.
 * Uniquely the Second Doctor is the only incarnation who didn't regenerate at the end of his last regular appearance, instead his regeneration was shown in the comic story The Night Walkers, also making the Second Doctor the only incarnation to regenerate outside of the television series.
 * The Second Doctor was the only incarnation to emerge from his regeneration with a different set of clothes, as opposed to future incarnations who would have to find a new pair of clothes after changing out of the clothes worn by their previous incarnation.
 * The role of the Second Doctor in the Big Finish plays has been portrayed by close friend and fellow Who actor Frazer Hines, as Patrick Troughton had died 12 years prior to the company's first Who audio.