Sasanian conquest of Egypt
The Sasanian conquest of Egypt took place between 618 and 621 CE, when the Sasanian Persian army defeated the Byzantine forces in Egypt and occupied the province. The fall of Alexandria, the capital of Roman Egypt, marked the first and most important stage in the Sasanian campaign to conquer this rich province, which eventually fell completely under Persian rule within a couple of years. An account of the event is given by A. J. Butler.