The clashes narrated so far all happened in the southern parts of the Levant and Iraq and quite close to the Syrian desert. By contrast contemporary observers report no battles occurring in the northern parts of these regions. This is possibly because settlements there all submitted to the Arabs without a fight. They had already suffered badly in the earlier Byzantine-Persian war of 603—28 and so would have been discouraged from making a stand, especially when news came in of the recent Arab successes in the south. The only other theater of war that we hear of is the Jazira. This term means “island” in Arabic and it refers to the territory that is virtually encircled by the northern arms of the mighty Euphrates and Tigris Rivers, comprising parts of modern northwest Iraq, northeast Syria, and southeast Turkey. It was the heartland of Aramaic Christianity, as indeed it still is today, though there are dramatically fewer Christians there now. “The whole land of the Jazira,” wrote one local resident, “was rich in vineyards, fields and much cattle; there was not one single poor and miserable man in any village who did not possess a plough, donkey and goats.”24 There were also large areas of steppe well suited to grazing and these were the preserve of a number of powerful Arab pastoralist tribes. The territory's wealth meant that it was attractive to great powers and indeed was fought over by Byzantium and Persia for many centuries before becoming a border zone between the Byzantine and Arab states.
The Arab commander in Syria, Abu 'Ubayda, entrusted his kinsman 'lyad ibn Ghanm, a man famed for his generosity, to oversee the subjugation of the cities of northern Syria. In 638, while 'lyad was at the encampment of Qinnasrin, near the great Hellenistic city of Chalcis and just south of modern Aleppo, the governor of Byzantine Mesopotamia, John Kataias, came to meet him. His mission was to save his province from Arab occupation, but he did not have sufficient troops to achieve this aim by military means. Instead he promised to pay 'Iyad every year 100,000 gold coins “on condition that he would not cross the Euphrates either peacefully or by force of arms as long as that amount of gold was paid to him.”25 'Iyad agreed and John, true to his word, returned to Mesopotamia to collect the annual tribute and then dispatched it directly to 'lyad. However, the emperor Heraclius, on hearing about this deal, was furious that it had been arranged without his knowledge; he dismissed John and exiled him to Africa and replaced him with a military man, a general named Ptolemy.
When the next year’s tribute payment was due, Ptolemy refused to authorize it and so 'lyad crossed the Euphrates with an army and in the course of the year 639-40 he visited each city in turn to demand its submission. He began with Edessa in the west of the region and gradually made his way over to Nisibis in the east. The former opened its gates to him and was rewarded with a favorable treaty, which respected its inhabitants’ lives and property and even allowed Ptolemy, who was based there, to leave for Byzantine territory together with his soldiers. The same conciliatory approach was taken by most of the nearby cities and they too were given generous terms. Tella and Dara, however, decided to resist. The former prepared for a siege, but 'lyad launched a determined assault and after capturing it killed its guard of 300 soldiers. Dara lay right by the former Byzantine-Persian border and had endured Persian attacks many times before and so perhaps felt able to withstand an Arab advance (Figure 2.5), but it too was fairly quickly reduced and its resident soldiery was wiped out. 'lyad then returned to Qinnasrin and for the next few decades the Jazira was governed from this distant base. This remoteness meant that Arab involvement in the province’s affairs was minimal. We hear of no substantial Arab settlement, as occurred in Iraq and Syria, and being now isolated from the Byzantine realm it was no longer a focus of imperial patronage or persecution. Existing patterns of local government and tax-collection were left mostly intact: in the former Persian part of the region the same local aristocratic families were in charge as before the conquest, and Greek-educated Christians managed the ex-Byzantine lands. “The Christians were still the scribes, leaders and governors,” observes one chronicler,26 and this seems to have remained the case at least until the end of the seventh century.