Lewis, the son of Charles the Great, was a prince who had very much of good in him, so that he is commonly called the Pious. But he was of weak character, and his reign was full of troubles, mostly caused by the ambition of his own sons, who were helped by a strong party among the clergy, and even by Pope Gregory the Fourth. At one time he was obliged to undergo public penance, and some years later he was deprived of his kingdom and empire, although these acts caused such a shock to the feelings of men that he found friends who helped him to recover his power. And after his death (AD 840) his children and grandchildren continued to quarrel among themselves as long as any of them lived.
Besides these quarrels among their princes, the Franks were troubled at this time by enemies of many kinds.
First of all I may mention the Northmen, who poured down by sea on the coasts of the more civilized nations. These were the same who in our English history are called Danes, with whom the great Alfred had a long struggle, and who afterwards, under Canute, got possession of our country for a time. They had light vessels-- serpents, as they were called--which could sail up rivers; and so they carried fire and sword up every river whose opening invited them, making their way to places so far off the sea as Mentz, on the Rhine; Treves, on the Moselle; Paris, on the Seine; and even Auxerre, on the Yonne. They often sacked the wealthy trading cities which lay open to their attacks; they sailed on to Spain, plundered Lisbon, passed the Straits of Gibraltar, and laid waste the coasts of Italy.
After a time they grew bolder, and would leave their vessels on the rivers, while they struck across the country to plunder places which were known to be wealthy. They made fortified camps, often on the islands of the great rivers, and did all the mischief they could within a large circle around them. These Northmen were bitter enemies of Christianity, and many of them had lost their homes because they or their fathers would not be converted at Charlemagne's bidding; so that they had a special pleasure in turning their fury against churches and monasteries. Wherever they came, the monks ran off and tried to save themselves, leaving their wealth as a prey to the strangers. People were afraid to till the land, lest these enemies should destroy the fruits of their labours. Famines became common; wolves were allowed to multiply and to prey without check; and such were the distress and fear caused by the invaders, that a prayer for the deliverance "from the fury of the Northmen" was added to the service-books of the Frankish Church.
Another set of enemies were the Mahometan Saracens, who got possession of the great islands of the Mediterranean and laid waste its coasts. It is said that some of them sailed up the Tiber and carried off the altar which covered the body of St. Peter. One party of Saracens settled on the banks of a river about halfway between Rome and Naples; others in the neighbourhood of Nice, and on that part of the Alps which is now called the Great St. Bernard; and they robbed pilgrims and merchants, whom they made to pay dearly for being let off with their lives.
Europe also suffered much from the Hungarians, a very rude, heathen people, who about the year 900 poured into it from Asia. We are told that they hardly looked human, that they lived like beasts, that they ate men's flesh and drank their blood. They rode on small active horses, so that the heavy-armed cavalry of the Franks could not overtake them; and if they ran away before their enemies, they used to stop from time to time, and let fly their arrows backwards. From the Elbe to the very south of Italy these barbarians filled Europe with bloodshed and with terror.
The Northmen at length made themselves so much feared in France, that King Charles III, who was called the Simple, gave up to them, in 911, a part of his kingdom, which from them got the name of Normandy. There they settled down to a very different sort of life from their old habits of piracy and plunder, so that before long the Normans were ahead of all the other inhabitants of France; and from Normandy, as I need hardly say, it was that William the Conqueror and his warriors came to gain possession of England.
The princes of Charles the Great's family, by their quarrels, broke up his empire altogether; and nobody had anything like the power of an emperor until Otho I, who became king of Germany in 936, and was crowned emperor at Rome in 962.