provinces, and which gave both the Empire and the Teutonic kingdoms of the West an enemy of a kind altogether different from any against whom they hitherto had to strive. ♦Rise of the Saracens.♦ The cause which wrought such abiding changes was the rise of the _Saracens_ under Mahomet and his first followers. A new nation, that of the Arabs, now became dominant in a large part of the lands which had been part of the Roman Empire, as well as in lands far beyond its boundaries. ♦Arabia united under Mahomet, 622-632.♦ The scattered tribes of Arabia were first gathered together into a single power by Mahomet himself, and under his successors they undertook to spread the Mahometan religion wherever their swords could carry it. And, with the Mahometan religion, they carried also the Arabic language, and what we may call Eastern civilization as opposed to Western. A strife, in short, now begins between Aryan and Semitic man. Rome and Persia, with all their differences, were both of them Aryan powers. ♦Conquests of the Saracens.♦ The most amazing thing is the extraordinary speed with which the Saracens pressed their conquests at the expense of both Rome and Persia, forming a marked contrast to the slow advance both of Roman conquest and of Teutonic settlement. In the course of less than eighty years, the Mahometan conquerors formed a dominion greater than that of Rome, and, for a short time, the will of the Caliph of the Prophet was obeyed from the Ocean to lands beyond the Indus. ♦Loss of the Eastern provinces of Rome. 632-639.♦ In a few campaigns the Empire lost all its possessions beyond Mount Tauros; that is, it lost one of the three great divisions of the Empire, that namely in which neither Greek nor Roman civilization had ever thoroughly taken root.