wrests the stolen provinces from the hands of the invader, and presses far into his enemy's territory with crushing effect. No sooner has this military miracle been achieved than a new and totally unexpected enemy comes up from the desert and defeats the victorious Byzantine power, to the amazement and dismay of the empire. The Arabs, tired by the new creed of Islam, tear off Syria, Egypt, and southern regions farther West, leaving only a mutilated torso to represent the ancient Roman Empire. Yet in vain does the mighty flood gather to sweep this remnant away. Constantinople still remains a virgin fortress, impregnable. Miserable times follow. The Mohammedans raid Asia Minor; tribes from the Danubian countries pour over Macedonia and Greece; the empire is virtually reduced to the limits of the one city of Constantinople. Now indeed it might appear as though the ancient Roman dominion in the East were approaching final dissolution. But that is not to be its fate. It has been called "effete," but still it displays marvellous vitality.
What is the explanation of this remarkable vitality? In part, the persistence of the empire through all the vicissitudes of fortune is to be attributed to its just judicature and skilful administration of government. The Roman law was well applied all through these changing times, and the machinery of government was worked with scientific exactness. Nowhere else in the world was the art of government so ably practised. Constantinople was the centre of civilisation in politics as well as in art and letters. Still, civilisation cannot be self-supporting. If the vigour of the "early caliphs had been preserved by their successors no human power could have saved the world from the overthrow of the Christian religion as well as the destruction of European culture. Even after the ardour of missionary zeal among the Mohammedans had cooled they were still formidable, and when reinforced by the Turks, almost invincible. Then deliverance came from one of the most powerful men of history. It has been pointed out that while Charles Martel has
