[3] Born in London, Dempster made his stage debut in 1920, and began his screen career in the silent film era.

[4] His credits included Vice Versa, Anna Karenina, The Winslow Boy, The Fan, Scrooge, The House Across the Lake and The Ghost Train (short film).

[5] During World War II, Dempster served in the Royal Air Force.

[3] Thirty-six years separated Dempster's first and last appearances on Broadway.

[6] He debuted in the 1929 melodrama Rope's End by Patrick Hamilton and in 1965 replaced Peter Sallis as Dr. Watson in the Sherlock Holmes-inspired musical Baker Street.