CEVAP:

The Sasanian Empire included the territory that is now Egypt, most of the shoreline of modern Saudi Arabia, nearly all of modern day Turkey, and the entire region of the Caucasus. The Sasanian Empire lasted for over 400 years on the eastern border of the Byzantine Empire, and was able to take over much of the territory west of Greece when it collapsed. This gave the Sasanian Empire its greatest size just before the beginning of Islam. It also meant that the Empire was extended to its farthest reaches.