Castle Keep is a "firmly pro- and anti-war" 1969 American war film combining surrealism with tragic realism. It was directed by Sydney Pollack and starred Burt Lancaster, Patrick O'Neal, Jean-Pierre Aumont, Bruce Dern, and Peter Falk. The movie appeared in the summer of 1969, a few months before the arrival of Pollack's smash hit They Shoot Horses, Don't They?.The film is based on a novel by William Eastlake published in 1965. Eastlake enlisted in the US Army in 1942.