Emperor Heraclius no relation Siege of Damascus (634)
After most of the Syrian countryside was conquered by the Rashidun Caliphate during the reign of Caliph Umar (r. 634–644), Damascus itself was conquered by the Arab Muslim general Khalid ibn al-Walid in August–September 634 CE. His army had previously attempted to capture the city in April 634, but without success. With Damascus now in Muslim-Arab hands, the Byzantines, alarmed at the loss of their most prestigious city in the Near East, had decided to wrest back control of it. Under Emperor Heraclius, the Byzantines fielded an army superior to that of the Rashidun in manpower. They advanced into southern Syria during the spring of 636 and consequently Khalid ibn al-Walid's forces withdrew from Damascus to prepare for renewed confrontation. In August, the two sides met along the Yarmouk River where they fought a major battle which ended in a decisive Muslim victory, solidifying Muslim rule in Syria and Palestine. While the Muslims administered the city, the population of Damascus remained mostly Christian—Eastern Orthodox and Monophysite—with a growing community of Muslims from Mecca, Medina, and the Syrian Desert. The governor assigned to the city which had been chosen as the capital of Islamic Syria was Mu'awiya I.
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