Caliphate

The Caliphate is a (usually) Muslim nation that appears in the year 626 if playing from an earlier era. Caliphate usually exists from 626 to 1335, though it may survive a few years after that.

At its heyday in 713, Caliphate is the most powerful nation in the world, with nearly 200 provinces to boast. It is so powerful in 713 that it can even protect Byzantium, itself a major power at this time.

A good strategy for Caliphate is to take control of its immediate neighbours (Aksum has many useful resources, as does Khwarazmia) and only attack major powers if you have -200 unrest or less.