28. =Mohammedanism and the Carolingian Empire.=--A great change had passed over Europe since the days when a Frankish princess, by her marriage with the Kentish Ethelberht, had smoothed the way for the introduction of Christianity into England. In the first part of the seventh century Mohammed had preached a new religion in Arabia. He taught that there was one God, and that Mohammed was his prophet. After his death his Arab followers spread as conquerors over the neighbouring countries. Before the end of the century they had subdued Persia, Syria, and Egypt, and were pushing westwards along the north coast of Africa. In =711= they crossed the Straits of Gibraltar. All Spain, with the exception of a hilly district in the north, soon fell into their hands, and in =717= they crossed the Pyrenees. There can be little doubt that, if they had subdued Gaul, Mohammedanism and not Christianity would for a long time have been the prevailing religion in Europe. From this Europe was saved by a great Frankish warrior, Charles Martel (_the Hammer_), who in =732= drove the invaders back at a great battle between Tours and Poitiers. Charles's son, Pippin, dethroned the reigning family and became king of the Franks. Pippin's son was Charles the Great, who before he died ruled over the whole of Gaul and Germany, over the north and centre of Italy, and the north-east of Spain. His rule was favoured both by the Frankish warriors and by the clergy, who were glad to see so strong a bulwark erected against the attacks of the Mohammedans. At that time the Roman Empire, which had never ceased to exist at Constantinople, fell into the hands of Irene, the murderess of her son. In =800= the Pope, refusing to acknowledge that the Empire could have so unworthy a head, placed the Imperial crown on the head of Charles as the successor of the old Roman Emperors. 29. =Ecgberht's Rule. 802--839.=--Though Charles did not directly govern England, he made his influence felt there. Offa had claimed his protection, and Ecgberht took refuge at his court. Ecgberht doubtless learned something of the art of ruling from him, and in =802= he returned to England. Beorhtric was by this time dead, and Ecgberht was accepted as king by the West Saxons. Before he died, in =839=, he had made himself the over-lord of all the other kingdoms. He was never, indeed, directly king of all England. Kent, Sussex, and Essex were governed by rulers of his own family appointed by himself. Mercia, East Anglia, and North-humberland retained their own kings, ruling under Ecgberht as their over-lord. Towards the west Ecgberht's direct government did not reach beyond the Tamar, though the Cornish Celts acknowledged his authority, as did the Celts of Wales. The Celts of Strathclyde and the Picts and Scots remained entirely independent. CHAPTER IV. THE ENGLISH KINGSHIP AND THE STRUGGLE WITH THE DANES. LEADING DATES