In the meantime, i.e. in the course of the years 636 and 637, Shuraḥbīl and Yazīd had finally occupied the remainder of the interior, and most of the towns on the coast. 'Amr was less fortunate, and invested Jerusalem in vain. The stubborn Caesarea also remained for a time closed to the Arabs. It is no matter of chance that just these two strongly Hellenised towns should have held out. Their resistance gives us a clue to explain the rapid successes of the Arabs. The military power of the Emperor was certainly broken, and he lacked both men and money; but it was of much greater moment that everywhere in Syria, where Semites dwelt, the Byzantine rule was so deeply hated that the Arabs were welcomed as deliverers, as soon as there was no need further to fear Heraclius. To cover his enormous debts Heraclius had been compelled to put on the fiscal screw to its utmost tension. In addition to this domestic pressure there was added that of religion; the church policy of Heraclius, the introduction of the Monotheletic Irenicon, became a persecution of Monophysites and Jews. In addition to this religious division there was now further the natural reaction of the Semitic element against the foreign rule of the Greeks. In the Muslims on the other hand the numerous Christian Arab tribes, and even the Aramaeans too, welcomed blood relations; the tribute moreover demanded by the Arabs was not heavy, and finally the Arabs permitted complete religious freedom; in fact, for political reasons, they rather encouraged heterodox tendencies. Thus, after the Arabs had vanquished the tyrants, the land fell peacefully into their own possession. The resistance of Jerusalem and Caesarea affords the test of this theory, for both of these towns were entirely Hellenic and orthodox. Even these towns however were unable to maintain their position for any length of time, and Jerusalem capitulated as early as 638; Caesarea did not fall until October 640 into the hands of Mu'āwiya, and then only through treachery.
Even before the fall of Jerusalem the Caliph Omar had paid a visit to Syria. His appearance there was the result of the policy of occupation followed by Medina. The head-quarters of the Muslim army was at that time still at Jābiya, a little to the north of the Yarmūk battle-field. To this spot Omar summoned all his military commanders, presumably to support Abū 'Ubaida in his difficult task with the authority of the Caliph. Apart from this however it was desired to lay down uniform principles for the treatment of the subjected peoples, i.e. to define the difficult problem which we of modern times call native policy. Further, the disposition of the money coming in and the whole administration needed an initial regulation, or rather sanction. Later tradition considers Omar the founder of the theoretical system of the ideal Muslim State, but incorrectly so, as will be shewn later. At the same time an initial regulation then certainly took place. On the termination of his work of reorganisation Omar visited Jerusalem,
