It was no light task he had undertaken, and the great general made ready for it with the utmost care and deliberation. He was about to invade a country of great resources, of remarkable natural and artificial defences, and inhabited by a people celebrated for their fierceness and impetuosity, and who had hitherto known little besides victory. And he was to leave behind him in his march a kingdom full of unquiet elements, which needed the presence of his strong arm and quick mind to keep it in subjection. He knew not but that the Saxons might rise upon his march and spread ruin upon his path. There was one way to avoid this, and that he took. Years before, he had incorporated the Lombards with his army, and found them to fight as valiantly for him as against him. He now did the same with the Saxons, drafting a large body of them into his ranks, with the double purpose of weakening the fighting power of the nation, and employing their fierce courage in his own service. All winter the world of the Franks was in commotion, preparing for war. The chroniclers of the times speak of "innumerable multitudes" which the great conqueror set in motion in the early spring.
The army marched in three grand divisions. One entered Bavaria, joined to itself recruits raised in that country, and descended the Danube in boats, which carried also an abundance of provisions and military stores. A second division, under Charlemagne himself, marched along the southern side of the river; and a third, under his generals Theoderic and Meginfried, along its northern banks. The emperor had besides sent orders to his son Pepin, king of Italy, bidding him to lead an army of Lombards and other Italians to the frontier of Hungary, and co-operate with the other troops.
Before telling the story of the expedition, it behooves us to give some account of the country which the king of the Franks was about to invade, and particularly to describe the extraordinary defences and interior conditions with which it is credited by the gossipy old Monk of St. Gall, the most entertaining, though hardly the most credible, writer of that period. All authors admit that the country of the Avars was defended by an ingenious and singular system of fortifications. The account we propose to give, the Monk of St. Gall declares that he wrote down from the words of an eye-witness, Adelbart by name, who took part in the expedition. But one cannot help thinking that either this eye-witness mingled a strong infusion of imagination with his vision, or that the monk added fiction to his facts, with the laudable purpose of making an attractive story. Such as it is, we give it, without further comment.
Nine concentric circles of palisaded walls, says the garrulous old monk, surrounded the country of the Avars, the outer one enclosing the entire realm of Hungary, the inner ones growing successively smaller, the innermost being the central fortification within which dwelt the Chagan, with his palace and his treasures. These walls were made of double rows of palisades of oak, beech, and pine logs, twenty feet high and twenty feet asunder, the interval between them being filled with stone and lime. Thus was formed a great wall, which at a distance must have presented a singular appearance, since the top was covered with soil and planted with bushes and trees.
The outermost wall surrounded the whole country. Within it, at a distance of twenty Teutonic, or forty Italian, miles, was a second, of smaller diameter, but constructed in the same manner. At an equal distance inward was a third, and thus they continued inward, fortress after fortress, to the number of nine, the outer one rivalling the Chinese wall in extent, the inner one—the ring, as it was called—being of small diameter, and enclosing a central space within which the Avars guarded the accumulated wealth of centuries of conquest and plunder.
The only places of exit from these great palisaded fortifications were very narrow gates, or sally-ports, opening at proper intervals, and well guarded by armed sentinels. The space between the successive ramparts was a well-wooded and thickly-settled country, filled with villages and homesteads, so close together that the sound of a trumpet could be heard from one to the other, and thus an alarm from the exterior be conveyed with remarkable rapidity throughout the whole land.
This and more the veracious Monk of St. Gall tells us. As to believing him, that is quite another matter. Sufficient is told by other writers to convince us that the country was guarded by strong and singular defences, but the nine concentric circles of breastworks, surpassing the Chinese wall in length and size, the reader is quite privileged to doubt.
Certainly the defences failed to check the advance of the army of Charlemagne. Though he had begun his march in the spring, so extensive were his preparations that it was September before he reached the banks of the river Enns, the border line between Bavaria and Hungary. Here the army encamped for three days, engaged in prayers for victory, and here encouraging news came to Charlemagne. His son Pepin, with the Duke of Friuli, had already invaded Hungary, met an army of the Avars, and defeated it with great slaughter. The news of this success must have invigorated the army under Charlemagne. Breaking camp, they invaded the country of the Avars, advancing with the usual impetuosity of their great leader. One after another the Hungarian lines of defence were taken, until three had fallen, while the country between them was laid waste. No army appeared in the path of the invaders; sword in hand, Charlemagne assailed and broke through the strong walls of his foes; soon he reached the river Raab, which he followed to its junction with the Danube.
Until now all had promised complete success. Those frightful Huns, who had so long kept Europe in terror, seemed about to be subdued and made subjects of the great monarch of the Franks. But, through that fatality which so often ruins the best-laid plans of men, Charlemagne suddenly found himself in a perilous and critical situation. His army was composed almost wholly of cavalry. As he lay encamped by the Danube, a deadly pestilence attacked the horses, and swept them off with such rapidity that a hasty retreat became necessary. Nine-tenths of the horses had perished before the retiring army reached Bavaria. Good fortune, however, attended the retreat. Had the Avars recovered from the panic into which their successive defeats had thrown them, they might have taken a disastrous revenge upon the invaders. But as it was, Charlemagne succeeded in retiring without being attacked, and was able to take with him the valuable booty and the host of prisoners which were the trophies of his victorious progress.
He fully intended to return and complete the conquest of Hungary in the spring, and, to facilitate his advance, had a bridge of boats constructed, during the winter, across the Danube. He never returned, as it happened. Circumstances hindered. But in 794 his subject, the margrave Eric, Duke of Friuli, again invaded Hungary, which had in the interval been exhausted by civil wars. All the defences of the Avars went down before him, and his victorious troops penetrated to that inner fortress, called the Ring, which so long had been the boasted stronghold of the Chagans, and within whose confines were gathered the vast treasures which the conquering hordes had accumulated during centuries of victory and plunder, together with the great wealth in gold and silver coin which they had wrung by way of tribute from the weak rulers of the Eastern Empire. A conception of the extent of this spoil may be gathered from the fact that the Greek emperor during the seventh century paid the Avars annually as tribute eighty thousand gold solidi, and that on a single occasion the Emperor Heraclius was forced to pay them an equal sum.