The man Clint Eastwood would call his mentor began his movie career as a film librarian and editor. Born Oct. 26, 1912, Chicago native Don Siegel helmed two Oscar-winning short films before directing his first feature, the 1946 mystery The Verdict starring Peter Lorre.

Siegel quickly became known for making effective chillers and crime dramas such as Riot in Cell Block 11 (1954) and Invasion of the Body Snatchers (1956). It wasn't until the late 1960s, however -- when he began working with Eastwood -- that Siegel established himself in viewers' minds. Between 1968 and '79, Siegel directed Eastwood in a series of action thrillers that cemented both men's reputations, including Two Mules for Sister Sara, Dirty Harry and Escape from Alcatraz.

Other important movies for Siegel include 1960's Flaming Star (with Elvis Presley) and The Shootist (1976). Siegel succumbed to cancer April 20, 1991.