The Kobal Collection/Samuel Bronston

By the time of The Fall of the Roman Empire (1964), audiences had already been treated to a re-creation of ancient Rome in Quo Vadis (1951) and a magnificent Roman-period arena in Ben-Hur (1959). Those sets, however, were dwarfed by the Fall’s enormous Roman Forum (pictured), which featured 27 three-dimensional structures and 1,000 relief panels. Unfortunately for Hollywood, 1960s moviegoers were losing their taste for gaudy Roman epics, and the Fall proved to be an expensive flop.