and his own daughter Rothrude. In 786 the
entreaties of the pope and the hostile attitude of Arichis II., duke of
Benevento, a son-in-law of Desiderius, called the king again into Italy.
Arichis submitted without a struggle, though the basis of Frankish
authority in his duchy was far from secure; but in conjunction with
Adalgis he sought aid from Constantinople. His plans were ended by his
death in 787, and although the empress Irene, the real ruler of the
eastern empire, broke off the projected marriage between her son and
Rothrude, she appears to have given very little assistance to Adalgis,
whose attack on Italy was easily repulsed. During this visit Charles
had presented certain towns to Adrian, but an estrangement soon arose
between king and pope over the claim of Charles to confirm the election
to the archbishopric of Ravenna, and it was accentuated by Adrian's
objection to the establishment by Charles of Grimoald III. as duke of
Benevento, in succession to his father Arichis.

These journeys and campaigns, however, were but interludes in the long
and stubborn struggle between Charles and the Saxons, which began in 772
and ended in 804 with the incorporation of Saxony in the Carolingian
empire (see SAXONY). This contest, in which the king himself took a very
active part, brought the Franks into collision with the Wiltzi, a tribe
dwelling east of the Elbe, who in 789 was reduced to dependence. A
similar sequence of events took place in southern Germany. Tassilo III.,
duke of the Bavarians, who had on several occasions adopted a line of
conduct inconsistent with his allegiance to Charles, was deposed in 788
and his duchy placed under the rule of Gerold, a brother-in-law of
Charles, to be governed on the Frankish system (see BAVARIA). Having
thus taken upon himself the control of Bavaria, Charles felt himself
responsible for protecting its eastern frontier, which had long been
menaced by the Avars, a people inhabiting the region now known as
Hungary. He accordingly ravaged their country in 791 at the head of an
army containing Saxon, Frisian, Bavarian and Alamannian warriors, which
penetrated as far as the Raab; and he spent the following year in
Bavaria preparing for a second campaign against them, the conduct of
which, however, he was compelled by further trouble in Saxony to entrust
to his son king Pippin, and to Eric, margrave of Friuli. These deputies
succeeded in 795 and 796 in taking possession of the vast tre