promise of tribute: but although, from the way in which it is mentioned by Charles’s biographer it is evident that this campaign against the Wiltzi was an arduous one, it cannot be said to have produced any enduring results. Speaking generally, the Elbe remained the boundary of the Frankish kingdom. The various Sclavonic tribes on the other side of it were, to borrow a term from modern diplomacy, “in the Frankish sphere of influence,” but they were not obedient citizens of the Frankish state. We return to the affairs of the Avars. The year 790 was a quiet one, so much so that Charles, now verging on his fiftieth year, and “fearing to grow torpid through lack of exercise,” sailed up the Main and the Franconian Saale to his palace of Königshofen by the banks of the latter river, and returned in like manner to Worms. But even in this year there were discussions and altercations concerning boundaries with the ambassadors of the Avars. Charles was evidently making his preparations and accumulating materials for his case against the doomed nationality. Next year, 791, the storm burst, and Charles made his great, his only personally commanded expedition, into Avar-land. At a council of Franks, Saxons, and Frisians held at Ratisbon, it was decided that “on account of the great and intolerable malice which the Avars had shown towards the Holy Church and the Christian people, and the impossibility of obtaining justice at their hands by means of the royal messengers, a hostile expedition should march against them.” The whole army marched to the river Enns, the boundary of Avar-land, and there for three days sang litanies and witnessed solemn masses imploring God “for the safety of the army, the help of our Lord Jesus Christ, and victory and vengeance against the Avars.” Charles then, according to his usual custom, divided his army, marching himself along the south bank of the Danube, and sending the Saxon and Frisian auxiliaries with some Franks along the northern bank. The Avars had erected two strongholds, one on each side of the river, at a little distance above the modern city of Vienna: but they were struck with panic fear when they saw the two columns marching on either side of the river, and the ships (laden probably with provisions) sailing majestically between them. They abandoned their strongholds without striking a blow, “and so, Christ leading on his own people, both armies entered the country without sustaining any loss.” It was, in fact, a military promenade. Charles marched through the country, ravaging as he went, as far as the river Raab, and then, “after traversing and laying waste a great part of Pannonia, carried back his army safe and sound into Bavaria. This expedition was made without inconvenience of any kind, save that in that part of the army which the king commanded, so great a pestilence arose among the horses that scarcely the tenth part out of so many thousands of horses is said to have remained alive.” The king returned