CONQUEST OF SYRIA Details are wanting—we only know that in all the earlier battles the Romans had the worst of the game. That the conquest of Syria nevertheless took seven years (632-638) was only due to the fact that the Arabs, formidable in the charge, had no skill in siegecraft. Hence the long sieges of Damascus and Antioch, and the possibility of isolated strongholds like the sea girt Aradus holding out long after the bulk of the country had been overrun. In truth the invaders were not very numerous— if the regular Roman troops were also very limited in strength. And it was only gradually that the Arabs recruited their ranks with new hordes from the more recently converted corners of their own peninsula, and presently with renegades of all sorts, adven turers to whom plunder was all attractive, or disloyalists who thought Monotheism less repulsive than the theological formulae of their local enemies of the governmental faction.
It was the special luck of the Arab invaders that of the two realms which they invaded, Persia was ruled by a boy of newly elected as a compromise at the end of the bitter civil war, while in the Roman empire was reigning a worn-out veteran. Heraclius had been a brilliant leader in the old Persian campaigns, but he was now over sixty, and already smitten with the dropsy which ultimately proved fatal to him. He was in Syria for one year of the War only, and then retired to Constantinople, taking with him the "True Cross," which he had brought back to Jeru salem in triumph only five summers before. In the last period of his illness he appears to have been suffering intermittently from mental affliction. His brother Theodore and his son Constantine failed to replace him in a satisfactory fashion, and in five years more all Syria fell into the hands of the Muslims (633-638). Egypt, where the population was still more hostile and discontented, and where many of the officials behaved with absolute treachery, was lost in two more years (639-41). Only the great harbour at Alexandria was defended with any resolution. After Heraclius' death an expedition from Constantinople recovered it for a mo ment, but lost it within the year (646), and no Christian army was to be seen again in Egypt till the age of the Crusades.
In the first years of the Arab conquest of Roman and Persian territory, the military system adopted appears to have been that of establishing great garrison-centres in a limited number of places selected for their strategical importance—Basrah and after wards the more famous Kufa were the original bases on the Persian side, Damascus that on the Syrian; Fostat (Old Cairo) was the military centre of Egypt. Though detachments might be made to hold places of less importance, the armies were generally organised in and started from one of these base-camps. The organisation was at first tribal. North Arabian and South Arabian sections being formed in each great camp, and ere long many bodies of "clients," newly converted Syrian or Persian renegades, who were admitted to share the fortunes of the original invad ers. In the second generation there was little difference between the original Muslims and their adopted comrades.
When the first rush of Conquest was over, and permanent dy nasties, first the Ommayads and then the Abbasides, had replaced the elective Caliphs of the early years, the first signs of a change in military organisation were soon seen. The Caliph, like all ori ental princes, took to keeping large bodies of royal guards, who both guaranteed the safety of his person, and formed the solid nucleus of any army with which he took the field. These merce naries were at first Arabs, but before the end of the Ommayad dynasty strangers had already begun to replace them, and the Abbasides of the long-lived second caliphate line, regularly em ployed Soudanese Blacks, Persians, and above all Turks. The native Arabs had been found too factious and independent : the Turks, useful tools under a strong sovereign, ended by becoming their employers' masters, when the later Abbasides sank into de bility, and like the Praetorian guards of Rome and the Mamelukes in Egypt, they became king-makers. But this disgrace was still far off in 750, when the first Caliph of the second dynasty mounted the throne.