Age of Empires II: The Age of Kings is a real-time strategy video game developed by Ensemble Studios and published by Microsoft. Released in 1999 for Microsoft Windows and Macintosh in 2001, it is the second game in the Age of Empires series. The Age of Kings is set in the Middle Ages and contains 13 playable civilizations. Players aim to gather resources, which they use to build towns, create armies, and defeat their enemies. There are 5 historically based campaigns, which conscript the player to specialized and story-backed conditions, and 3 additional single-player game modes; multiplayer is also supported.