Frazer Hines
Hines' "Doctor Who" debut came in 1966, when he was cast to play the part of Jamie McCrimmon, the companion of the Second Doctor (played by Patrick Troughton). Originally intended as a one-off guest character, Jamie joined the regular cast and appeared in the series from 1966 to 1969. Hines reprised the role in a cameo in the 20th anniversary serial "The Five Doctors" (1983) and as a guest star in "The Two Doctors" (1985). Hines would appear in 117 episodes of "Doctor Who" in all—more than any other "companion" actor in the history of the series. The only actors appearing in more episodes are those who played the first four Doctors. Many of the episodes featuring Jamie no longer exist in the BBC's collection.
History of Doctor Who
It was announced on 4 August 2013 on a live BBC special entitled "Doctor Who Live: The Next Doctor" that Peter Capaldi would portray the twelfth incarnation of the Doctor in 'Doctor Who'. During his appearance in the special, he said that he had been a fan of the series; a letter that he had written to the Radio Times at the age of 15 about the show was read aloud. Capaldi had already appeared in the series 4 episode "The Fires of Pompeii" as Caecilius, the father of the family that the Doctor saves from the eruption of Mount Vesuvius. He had also appeared in "" as the civil servant John Frobisher.