Arabs Conquer Mesopotamia, Syria and Palestine, 634-38 CE

The momentum generated by victories against dissidents and breakaway regions left Islamic warriors restless and aggressive. Moreover, Arabia was in an economic recession, trade having come to a standstill with ten years of war, and some of Islam's warriors were hungry for booty. They began making raids into Mesopotamia -- an alternative to raiding "the faithful" in Arabia. Mesopotamia was still nominally under the rule by the Persian Sassanid dynasty. It was three years since Constantinople and the Persians had ended their ruinous war. Anarchy reigned in the Sassanid Empire. The Muslim raiders into Mesopotamia found little resistance, and success encouraged more and bigger raids, launching one of the greatest imperialisms of all time. The caliph, Abu Bakr, went along with it. Finding Islam's warriors joyous in their victories, he declared a holy war on their behalf.

Bakr sent troops northwest into Palestine. In 634, at Ajnadia, about twenty miles west of Jerusalem, in another of history's great battles, Islam's army defeated an army sent by Constantinople. There the Muslim army benefitted from a weakened Constantinople and from their higher morale and superior mobility.

Bakr died without learning of the great victory in Palestine, and the successor he had chosen, Umar ibn-al-Khattab, became caliph. Umar (Omar) had been an early convert to Islam and had been one of Muhammad's closest companions. His succession had been a recommendation to the Islamic community, and from that community came a ratification of sorts but without any established mechanism for expression of popular will.

Like Bakr, Umar lived frugally. It is said that he owned only one shirt and slept on a bed of palm leaves. His rule began with the siege of Damascus -- Islamic forces still combating Constantinople's imperial forces. Six months later, in September 635, Damascus capitulated, and the usual treaty of empires was made with the city, the conquerors promising the people of Damascus protection in exchange for taxes.

Against the Muslim force in southern Mesopotamia, the Sassanid empire sent an army that included elephants, and they defeated the Muslims. But in subsequent battles Islamic warriors overcame their fear of Persia's elephants. With their swift horses and camels they bypassed fortresses and defeated Sassanid armies. After their victory at the Battle of Qadisiya in 637, the Muslim army was able to move across the whole of Mesopotamia. In 638 they captured Ctesiphon, the Sassanid capital. Also in 638 they overran Jerusalem, then Caesarea fifty miles to the north. In only three years, the Arabs had conquered Syria, Palestine and Mesopotamia.

In Palestine and Syria, Umar's army had created the impression that they were warring against the Byzantine empire rather than against local people, and the local Christians looked upon the emperor at Constantinople as an enemy. They were Monophysite Christians, abused by the Trinity-believing emperors seeking religious conformity.

Generally the Islamic forces had been disciplined, while fighting on empty stomachs and depending upon plunder for their meals. The conquerors had taken over the land and houses that had been abandoned by those fleeing to Constantinople. The conquerors had plundered the wealthy while in general the common people (who had little to plunder) found them well-behaved.

With conquest by the Muslims had come no missionaries attempting to interfere with the religious beliefs and practices of local people. People could worship as they pleased, but they were given the choice of converting to Islam or paying taxes. If they both refused to pay taxes and refused to convert to Islam they were subject to the penalty of death.