After achieving the victory of Wacûsa, Khâlid delivered over to Abu Obeida the despatch from the new Caliph, which (as we have related) was put into his hands at the commencement of the action, and with it surrendered the commission which he held from Abu Bekr.[228] The other leaders were all confirmed in their commands by Omar. [Sidenote: Khâlid loyally supports Abu Obeida.] The affront put upon him by Omar did not damp the zeal or devotion of Khâlid. He placed himself forthwith at the command of Abu Obeida, who published with reluctance the order for his deposition.[229] Abu Obeida knew full well the rare military genius of Khâlid; and, himself of a mild and unwarlike turn, was wise and magnanimous enough to ask, and as a rule implicitly to follow, his advice. Khâlid, nobly putting aside his grievance, devoted his best energies to the cause; and, his supersession notwithstanding, remained thus virtually the chief captain of Islam in Syria. The course of Moslem victory in Syria advanced with little let or check. In Persia the struggle was not to save a limb, but life itself. [Sidenote: Byzantine struggle in Syria faint-hearted.]Here it was otherwise. Syria, indeed, contained the holy places and all that was dearest to the Byzantine people as the cradle of their faith. But, after all, it was, though fair and sacred, but an outlying province, of which a cowardly, supine, and selfish court could without vital injury afford the loss. There were, accordingly, no such mortal throes in Syria as on the plains of Chaldæa. [Sidenote: Abu Obeida advances on Damascus.] Leaving a strong detachment on the Yermûk to keep communications open with the south, the invading army resumed its march towards Damascus. On the way, news reached them that the city had been reinforced, and also that in Palestine the scattered fragments of the defeated army had re-formed in the valley of the Jordan, thus threatening the Moslem rear. The moment was critical, and Abu Obeida wrote for orders to the Caliph. The command of Omar was to strike a decisive blow at Damascus. The citadel of Syria gained, the rest was sure. Accordingly, a strong column under Abul Aûr and other veteran leaders was sent back to hold in check the enemy on the Jordan, while the main body advanced by the military road to Damascus. [Sidenote: Damascus.]