To replace the outgoing First Doctor William Hartnell, producers turned to veteran character actor Patrick Troughton, who not only ably handled the part but became a fan favorite in his own right. A World War II veteran, Troughton stayed in the role for three full seasons and well over 100 episodes. He turned the Doctor from a kindly father figure into a shabby, tramp-like character, proving the concept of regeneration could work.
During his tenure as the Second Doctor, the series blossomed and came into its own as an enduring icon of British television. It was during this era that the show established many of its more famous hallmarks, like the Doctor's odd eccentricities (such as playing a recorder), now-iconic adversaries like the Ice Warriors and The Great Intelligence, and the Earth-based organization U.N.I.T.
"Doctor Who" was hardly Troughton's only claim to fame, however. He had numerous appearances in "The Adventures of Robin Hood," and in big-screen classics like "Jason and the Argonauts," "The Omen," and Laurence Olivier's "Hamlet." Troughton returned to "Doctor Who" three times after stepping down, appearing in the 10th-anniversary episode "The Three Doctors," the 20th-anniversary special "The Five Doctors," and the 1985 serial "The Two Doctors." He was also very active on the "Doctor Who" convention circuit. Troughton died after suffering a heart attack in 1987.
