Caesar III is a city-building game released on September 30, 1998, for Microsoft Windows and Mac OS, developed by Impressions Games and published by Sierra On-Line. It is the third installment of the Caesar series of games and is part of Sierra's City Building series. Players assume the role of a provincial governor to build thriving cities across the Roman Empire, in which they must ensure their citizens have their needs met, and deal with various disasters, angry gods and hostile enemies.