proceeded to the pacification of the conquered country, without giving further heed to the Byzantines, from whom they did not consider they had anything more to fear. The various leaders operated in Palestine and the country east of the Jordan; Khālid himself pressed forward once more against Emesa, and occupied this place at the close of the year 635. A number of smaller towns hereupon opened their gates to the conquerors whilst the larger fortresses such as Jerusalem, Caesarea, and the coastal towns, still held out in hope of rescue by Heraclius.
Heraclius certainly as yet had no intention of giving up the country to the Arabs. He shewed a feverish activity in Antioch and Edessa. Together with the customary Byzantine mercenaries, Armenians and Arabs formed the main body of his new army, which he placed under the command of Theodorus Trithurius, and in which Baanes had the control of an independent division. The relief of Damascus not having been effected, Heraclius permitted the winter months to pass, intending when he was so much the better prepared to take the offensive and strike a crushing blow against the Arabs. In the spring of 636 this new army unexpectedly approached Emesa, where Khālid was on outpost duty. He at once recognised his dangerous position. Hitherto the Arabs had always fought against an inferior Byzantine force, but now they were suddenly opposed by a powerful army which, even after making all allowance for Arab exaggeration, must have amounted to some 50,000 men. Khālid immediately relinquished not only Emesa but even Damascus and caused all the Arab fighting forces to be concentrated at a point between the northern and southern positions of the Arabs in the country east of the Jordan, to the south-east of the deep Yarmūk valley, and to the north of what is now known as Der'āt, a point admirably adapted to his purpose. Here the Arabs were in the most fertile part of Syria, where the most important highways crossed leading to the southern portion of the country east of the Jordan and to Central Palestine; they were moreover protected in the rear by the deeply hollowed valleys of the Yarmūk tributaries. Should they be defeated here a retreat was under all circumstances secured either into the desert or to Medina. The hurried retirement of the Arabs to this district proves how critical affairs appeared to them: against the huge advancing army of the enemy, they could only oppose about 25,000, scarcely half the number.
The Roman army did not approach by way of Damascus but through Coelesyria and across the Jordan, and probably took up their position near Jillīn, the Jillīḳ of the sources. The two armies must have remained confronting each other for a considerable period: the Arabs were waiting for reinforcements, whilst the Byzantine army was hampered by the petty jealousies of its leaders and by insubordination in the ranks. Several battles were fought in which Theodorus appears to have been at the outset defeated and Baanes was then proclaimed emperor by the troops. The Arabian auxiliaries deserted,
