16 A Short History of the Middle East in Egypt the Patriarch of Alexandria had attempted to impose a doctrinal compromise on the Monophysite Copts by force, and in his complementary role of civil governor had been ruthless in the collection of taxes, with the result that the Coptic Bishop of Alexandria ordered his coreligionaries not to resist the Arabs. The only effective resistance to them came therefore from such centres of Greek civilization as Alexandria, Caesarea, and Jerusalem; and by 660, one generation after Mohammed's death, his green banner was flying over an empire which extended from Persia in the east, through the Fertile Crescent, Egypt, and Libya, to Tunisia in the west. Of these the only country to offer a deter- mined resistance was Persia, which had been the seat of an empire with a thousand-year-old tradition of proud domination. It is this period of conquering puritanism, of the very essence of Islam, and not the great age of cosmopolitan culture that was to follow, which Muslims themselves have always regarded as their Golden Age, the age of the rightly-guided (Rashidun) caliphs.1 The task of improvising an administrative system for the vast Arab empire was taken up in the main by the second caliph 'Umar. Authority in the provinces was placed in the hands of the Arab military commanders who had conquered them. Arab garrisons were established in newly-created cantonments in each of the con- quered countries, of which Fustat, by Old Cairo, and Basra in Lower Iraq, are examples. In order to maintain their separate identity from the conquered peoples the Arabs were not at first allowed to acquire land outside Arabia. Civil administration was left in the hands in which the Arab conquerors found it—Christians of Greek education in the lands of the Roman Empire, and non- Muslims of Persian education in the lands of the former Persian Empire. It is doubtful whether Arabs, in the stricter racial sense, have ever acquired any taste, or much aptitude, for such prosaic occupations. For the Muslim conquerors themselves the Qur'an, the com- pilation of the divine revelations received by Mohammed through- out his ministry, provided the rudiments of a civil and criminal code of laws, as enunciated by him in the ten years in which he governed the Muslim community at Madina. This was supple- mented where necessary by reference to what Ms Companions could remember of his day-to-day habits, his Sunna or custom; 1 Christopher Dawson, op. cit., 143.