premise: Tom Baker is incapable of having any acting roles.
hypothesis: Tom Baker ( August 23 , 1940 -- September 2 , 1982 ) was an American actor who starred in the Andy Warhol film I , A Man ( 1967 ) . Thomas Stewart `` Tom '' Baker ( born 20 January 1934 ) is an English actor . He is known for his portrayal of the fourth incarnation of the Doctor in the science fiction series Doctor Who from 1974 to 1981 , a longer tenure than any other actor , and for the narration of the comedy series Little Britain . Baker was in his thirties when his professional acting career began , and his first major film role was as Grigori Rasputin in Nicholas and Alexandra in 1971 , when he was 37 . He went on to play the villainous Prince Koura in The Golden Voyage of Sinbad in 1973 , which led to his casting in Doctor Who .