After William Hartnell had to retire from the role of the Doctor, the writers had quite a job on their hands to keep the show going without the lead actor. A few ideas were thrown around, including making a son of the Doctor, who would take his place upon his character's death. What they ended up going with, however, is one of the most innovative pieces of sci-fi lore: regeneration. By giving the Doctor's species the ability to change bodies upon their death, they allowed for the character to be changed out for new actors as much as was needed, essentially giving the show an unlimited potential run time.
Originally, regeneration was supposed to be a turning back of the Doctor's age. Hartnell's replacement, Patrick Troughton, was originally going to simply be a younger version of the first Doctor. As he went on, however, the idea was changed so that the new Doctor was an almost entirely different person from his predecessor. Essentially, the Doctor remains the same man with the same values, but different aspects of his personality are highlighted in different incarnations.
Now I will admit that I have not seem much of the second Doctor, but in fairness, no one my age has. There is only one complete story arc of his still in existence, as most of the film from his era was lost when a BBC building caught fire.
Patrick Troughton, the second Doctor, was often referred to affectionately as the “Cosmic Hobo”, due to his costume, which included the bow tie that inspired the costume of today's Matt Smith.
The second Doctor was cunning, quick witted, and always a few steps ahead of everyone else, but he often pulled a Jack Sparrow: pretending to be a total idiot while subtly setting up his plans. He was also fond of playing the recorder, his trademark hobby.
What really set the Troughton era apart from the Hartnell period was the style of the stories. While Hartnell's stories were often a mix of historic fiction and sci-fi, Troughtons were almost solely the latter. Even when his Doctor did visit the past, he would encounter an alien presence, rather than simply interact with the historic figures he'd meet. The writers also took full advantage of Troughton's age, as he was much younger than Hartnell, his stories could be much more fast paced, and much for action oriented. The stories became “monster of the week”, and the show eventually came under fire for its frightful content.
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| This was apparently what was considered terrifying in the late 60's |
The major new element that was introduced in the Troughton era was the introduction of the Doctor's species: the Time Lords. At the end of his time with the show, the second Doctor was forced to seek their help in returning a group of temporally displaced humans to their corrects eras. He was arrested, and put on trial for breaking the Time Lord codes of non-interference. He was banished to earth, his TARDIS was disabled, and he was forced to regenerate once more.
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| There are some corners of the universe which have bred the most terrible things. Things which act against everything we believe in. They must be fought. |
