Against such a conceivable fate of Europe Charlemagne served as a mighty bulwark, and built by his genius an impermeable wall against the torrent of savage invasion, saying to its inflowing waves, "Thus far shalt thou come, and no farther." Attila, the "Scourge of God," in the track of whose horses' hoofs "no grass could grow," met his only great defeat at Chalons-sur-Marne, on the soil of Gaul. He died in Hungary; his hordes were scattered; Europe again began to breathe. But not long had the Huns of Attila ceased their devastations when another tribe of Hunnish origin appeared, and began a like career of ravage and ruin. These called themselves Avars. Small in numbers at first, they grew by vanquishing and amalgamating other tribes of Huns until they became the terror and threatened to become the masters of Europe. Hungary, the centre of Attila's great circle of power, was made their place of abode. Here was the palace and stronghold of their monarchs, the Chagans, and here they continued a threat to all the surrounding nations, while enjoying the vast spoils which they had wrung from ruined peoples. Time passed on; civilization showed feeble signs of recovery; France and Italy became its abiding-places; but barbarian invasion still threatened these lands, and no security could be felt while the hordes of the north and east remained free to move at will. This was the task that Charlemagne was born to perform. Before his day the Huns of the east, the Saxons of the north, the Moors of the south kept the growing civilization of France in constant alarm. After his day aggression by land was at an end; only by sea could the north invade the south. The record of the deeds of Charlemagne is a long one. The Saxons were conquered and incorporated into the kingdom of the Franks. Then collision with the Avars took place. The story of how Charlemagne dealt with these savage hordes is one of the most interesting episodes in the extended tale of his wars, and we therefore select it for our present theme. The Avars had long been quiet, but now again began to stir, making two invasions, one of Lombardy, the other of Bavaria. Both were repelled. Stung by defeat, they raised a greater army than before, and in 788 crossed the Danube, determined in their savage souls to teach these proud Franks a lesson, and write on their land in blood the old story of the prowess and invincibility of the Huns. To their alarm and astonishment they found themselves not only checked, but utterly routed, thousands of them being left dead upon the field, and other thousands swallowed up by the Danube, in their wild effort to swim that swollen stream.