Career: McCallum became an assistant stage manager, but National Service interrupted his career. He made his film debut in 1957's These Dangerous Years, and appeared in numerous British movies before moving to Hollywood in the early 1960s. He landed roles in Billy Budd and The Great Escape but it was his performance as Illya Kuryakin in The Man from UNCLE that made him a household name in 1964. The series ran until 1968, and a spin-off TV movie was made in 1983. He also released four albums in the 1960s. Other major projects include Colditz, The Invisible Man, Sapphire and Steel, Mother Love, Hear My Song, and Cluedo. Since 2003, he has starred in popular American drama NCIS, playing forensics expert Dr Donald 'Ducky' Mallard.