David Keith McCallum Jr. was a Scottish actor and musician. He gained wide recognition in the 1960s for playing secret agent Illya Kuryakin in the television series
The Man from U.N.C.L.E. His other notable television roles include Carter in
Colditz (1972–1974) and Steel in
Sapphire & Steel (1979–1982). Beginning in 2003, McCallum gained renewed international popularity for his role as NCIS medical examiner Dr. Donald "Ducky" Mallard in the American television series
NCIS. On film, McCallum notably appeared in
The Great Escape (1963).