Siege of Damascus (634) - Background

Background

In 610, during the Byzantine-Sassanid War of 602-628, Heraclius became the emperor of the Byzantine Empire after overthrowing Phocas. While Heraclius focused his attention on the internal affairs of his empire, the Sassanid Persians conquered Mesopotamia, overran Syria in 611 AD, and entered Anatolia to occupy Caesarea Mazaca. In 612, Heraclius expelled the Persians from Anatolia. In 613, he launched a counter offensive against Syria, but was decisively defeated.

Over the next decade, the Persians conquered Palestine and Egypt and Heraclius rebuilt his army, preparing for a new offensive, which he launched in 622. He achieved substantial victories over the Persians and their allies in the Caucasus and Armenia. In 627, he launched a daring winter offensive in against Persia in Mesopotamia, and won a decisive victory at the Battle of Nineveh. This victory threatened the Persian capital city of Ctesiphon.

Discredited by this series of disasters, Khosrau II was killed in a coup led by his son Kavadh II, who at once sued for peace, agreeing to withdraw from all occupied territories of Byzantine empire. Heraclius restored the True Cross to Jerusalem with an elaborate ceremony in 629.

In Arabia, the Prophet Mohammad had united most of Arabia under a single religious and political authority. When Mohammed died in June 632, Abu Bakr was elected to the newly-formed office of Caliph, becoming Mohammad's political and religious successor. Several Arabic tribes revolted against Abu Bakr. In the Ridda wars (Arabic for the Wars of Apostasy), Abu Bakr quelled the revolt. By 633, Arabia was firmly united under the central authority of the Caliph in Medina. In 633, Abu Bakr initiated a war of conquest against the neighboring Sassanid Persian and the Byzantine empires. After a successful conquest of the Persian province of Iraq, Abu Bakr's confidence grew and in April 634 his armies invaded the Byzantine Levant from four different routes. These armies proved to be too small for the task, necessitating reinforcements from Iraq, led by Abu Bakr's capable general Khalid ibn Walid Crossing the desert, Khalid ibn Walid entered Syria from an unexpected route in a bold move. He attacked and overthrew the Byzantine defenses of Levant and quickly captured the Ghassanid capital city of Bosra. In July 634, the Muslim army under Khalid's command defeated another Byzantine army in the Battle of Ajnadayn. After clearing their southern flank, the Muslims laid siege to Damascus.