Rashidun Conquests

The Rashidun Caliphate expanded steadily; within the span of 24 years, a vast territory was conquered comprising Mesopotamia, the Levant, parts of Anatolia, and most of the Sasanian Empire.

Unlike the Sasanian Persians, the Byzantines, after losing Syria, retreated back to Anatolia. As a result, they also lost Egypt to the invading Rashidun army