THE RISE OF MOHAMMEDANISM 177 each other to a standstill, if not to the point of prostration, in a long series of wars. Heraclius had recovered Syria and Egypt, but these provinces were out of sympathy with Con- stantinople in religious matters and found their return to Byzantine taxation oppressive. Moreover, in Syria — and this was also true of Babylonia, the part of the Persian Kingdom next to Arabia — the mass of the population was Semitic, and so more in sympathy with the Arabs than with the Greeks of Constantinople or the Indo-Europeans of Persia. Within five years after Mohammed's death the Arabs had seized all Syria except Jerusalem and Caesarea. J They gained Babylonia by a victory in 637 and advanced to ! the Tigris, where the rich capital Ctesiphon was abandoned to them without a struggle. Mesopotamia was overrun in 64.1, and in ten years more the remainder of the Persian b«fi Kingdom had been conquered and its independent existence ended. Egypt, where the new Patriarch of Alexandria had been persecuting the Coptic Church, was conquered in the years 639-643. The Arabs next took to the sea, destroyed a large Byzantine fleet, and occupied the islands of Cyprus and Rhodes. Meantime by land they pushed weet from Egypt into Tripoli and north from Mesopotamia into Ar- menia. In 669 they advanced through Asia Minor to Chalce- don, crossed into Thrace and attacked Constantinople, but were repulsed. Then each year until 677 they made sea attacks upon the city, but all were failures, and the Arabs also withdrew from Rhodes. Nor for the remainder of the seventh century were they able to make any permanent advance into Asia Minor. In 716 Constantinople was once more attacked, but as usual weathered the storm. The Arabs did not force their conquered subjects to adopt Islam; they were willing to accept tribute from them in- stead and tolerated all Christian sects equally. Arabian Thus, some long- suffering heretical communities f t h e became free from persecution for the first time, conquered And the tribute was not as heavy as the imperial taxation had been. If, however, one turned Moslem, one no longer had to pay tribute and was far more likely to attain political
