Caliphate focuses on the rise and fall of Islamic civilization in the (approx.) 7th to 12th centuries. It is a game of conquest, trade, diplomacy, and building up your emirate economically, culturally, military, etc. Inspired by historical events, but not a strict historical simulation.
Players represent different Emirates that are rivals for control after Muhammed’s death at the end of his conquests. Each player controls an area on the map, along with a number of army units with which he can battle others and take over more territory.
In addition to combat, there are economic issues to attend to. Emirates produce a number of goods according to the size of area controlled, and players trade surplus commodities with each other to generate earnings. This trade income is combined with taxes to pay the required expenses of maintaining the army and to purchase infrastructure improvements.