Age of Empires is a series of personal computer games developed by Ensemble Studios and published by Microsoft Studios. The first title of the series was Age of Empires, released in 1997. Since then, seven titles and three spin-offs have been released. The titles are historical real-time strategy games, and their gameplay revolves around two main game modes: Single player and campaign. They competed with another popular strategy series, Civilization, and are set amidst historical events.