The punishment was to be of an eternal nature in the next world, and extirpation in this, unless they embraced Islâmism. Mohammed very soon began to make his power felt; he made a few marauding expeditions throughout the country, and gained many converts, especially when they became convinced that Islâm was to conquer the whole world by the sword. His army, however, was nearly annihilated by the Byzantine emperor, Heraclius, in a battle at Muta, but he recovered himself, and marched on to Mecca, where he put to the sword all those that did not embrace his religion, and destroyed all the remaining idols in the city. He allowed his army all the plunder they could get, after he had a tithe to himself, but it is said that he led a very abstemious life, dressed poorly, and resided with his wives in the shabbiest type of dwellings. He died in A.D. 632, or ten years after the Hegira, from which event is dated the Mohammedan era. After his death many of the converts became backsliders, but his successor, Abu-Bekr, and more especially the renowned Omar—the second caliph—brought the Saracens to a great power. They were very warlike, and capable of enduring great hardships, and as they had everything to gain and nothing to lose, they made war their sole trade, and carried their successful arms to India, Persia, Mesopotamia, Syria, Palestine, and Egypt. The islands of the Mediterranean, the northern coast of Africa, Spain, and the south-east of France, were by them also invaded, ravaged, and partly conquered. [Illustration: Fig. 343.—Alhambra Diaper, Superposed Ornament.] [Illustration: Fig. 344.—Stalactite Vaulting.]