 And for a couple of centuries, it was kind of a remote province of the Islamic Empire. But in 969, Egypt became an imperial center of its own. And several centuries after that, you could really think of Cairo, the capital of Egypt, as the New York City of its day. It was home to an enormous population. We estimate maybe half a million people at its height, which is more than twice as much as Paris, which is the largest city in Europe at the time.