To recover the thread of events in Syria, it is necessary to go back so far as the battle of Fihl. At the close of the fourteenth year of the Hegira, Abu Obeida, leaving Amru to follow up the victory in Palestine, and Yezîd as governor to hold Damascus, marched with the remainder of his forces northward upon Hims, from whence the emperor had been watching the progress of his enemies. He carried with him Dzul Kelâa, who, posted with his Himyar column beyond Damascus, had been, ever since the siege, covering the city from attack by the Romans on the north. They had advanced but a little way, when they were stopped by two Roman armies under Theodore and Shanas.[307] Dividing his forces, Abu Obeida took Shanas himself in hand, and left Khâlid to deal with the other. Damascus no longer covered, Theodore thought to make a sudden dash upon it. But Yezîd, with his garrison, was ready to confront him; and Khâlid, with a flying column, was immediately in pursuit. Taken thus before and behind, Theodore’s army was cut to pieces, but few escaping. Abu Obeida had meanwhile engaged Shanas and put him to flight. Meeting no further opposition, the Arabs continued their march, and attacked Báalbek, which after a short siege capitulated. [Sidenote: Hims [EMESSA] besieged.] Abu Obeida then advanced straight upon Hims, and closely invested it. Heraclius, on the defeat of Theodore, retired hastily on Roha,[308] from whence he endeavoured to raise the Bedouins of Mesopotamia with the view of effecting a diversion. [Sidenote: Dzul Cáda A.H. XIV. January, A.D. 636,]This effort (as we have seen) was defeated by Sád, who, making an inroad on Hît and Kirckesia, thus recalled the tribes to the defence of their desert homes. The siege of Hims, prosecuted with vigour, was bravely resisted. But the expectation of promised succour died away; the severity of winter failed to make the Arabs retire, the courage of the beleaguered garrison fell, and their sallies became less frequent and effective. When the siege had been thus protracted many weeks, suddenly an earthquake, with successive shocks, breached the battlements. [Sidenote: and taken, A.H. XV. Spring, A.D. 636.] The governor, finding the position no longer tenable, offered to capitulate; and the Moslems, unaware of the full extent of the mischief, readily gave the same terms to the prostrate city as had been given to Damascus. In answer to the despatch announcing the capture, and forwarding the royal share of the booty, Omar bade Abu Obeida to press forward; and promising further reinforcements, counselled him to gain over the powerful Bedouin tribes on the border, and strengthen his army thus. [Sidenote: March continued northwards.]