Byzantine Loss of Egypt

Timeline

1. 639–640Eastern frontier of Egypt · EgyptArab expedition commander Amr ibn al-As led his forces from Palestine into Egypt. Byzantine governor of Egypt Cyrus organized the defense, but the empire's main forces were exhausted by the war in Syria, and frontier fortresses such as Pelusium quickly fell.
2. 640Heliopolis · EgyptCyrus led the Byzantine army against the Arabs at Heliopolis and was decisively defeated. The ancient capital Memphis then fell, the heart of the Nile Delta came under Arab control, and Byzantine rule in Egypt was shaken to its foundations.
3. 641Alexandria · EgyptAfter a prolonged siege of the Mediterranean stronghold of Alexandria, the city's defenders finally surrendered. Cyrus and Amr signed a treaty, and Byzantine power withdrew from Egypt. The empire lost the gateway to trade with Africa and the Indian Ocean.
4. 641–642Egypt · EgyptBy 642, all remaining Byzantine forces in Egypt had been cleared out. The empire lost the "granary of Rome" and vast tax revenues; Constantinople's grain supply now depended on Anatolia and Black Sea trade, and the strategic focus was forced to contract to Asia Minor and the Balkans.