Second Doctor
The Second Doctor is an incarnation of the Doctor, the protagonist of the BBC science fiction television series "Doctor Who". He was portrayed by character actor Patrick Troughton.
Jon Pertwee
In 1969, Pertwee was selected by outgoing producer Peter Bryant and the series' next producer, Derrick Sherwin, to take over as the Doctor from Patrick Troughton in the television series "Doctor Who". Pertwee had asked his agent to apply for the role for him and was surprised to find he was already on the shortlist. He was the second choice for the role of the Third Doctor; Ron Moody was the first but was unavailable.