Avar March

During the same year, Avars made an incursion into Bavaria, but Franko-Bavarian forces succeeded in repelling them, and then launched a counterattack towards neighbouring Avarian territories, situated along Danube, eastern from Enns.

He held a council in Regensburg and regulated several issues regarding Bavarian frontier regions (marches),[9] thus preparing the basis for future actions towards the east.

Frankish army was advancing along the river Danube, divided in two columns, but neither of them found any active resistance, and soon both reached the region of Vienna Woods, at the gates of the Pannonian Plain.

[15] In the same time, further to the south, neighbouring Carantania, Carniola and southeastern Pannonian regions (Lower Pannonia) were left under the administration of their conqueror, king Pepin of Italy.

Charlemagne came to Bavaria and dispatched an army to the east, headed by new Bavarian prefect Audulf and frontier count Werner, commander of the eastern march, whose seat was in Lorch (ancient Roman Lauriacum, on the confluence of Enns and Danube).

Avarian princes converted to Christianity and continued to govern their people under the Frankish supreme rule, in the regions of Upper Pannonia, between Carnuntum and Savaria (modern Szombathely, in Hungary).

In the autumn of the same year, several Avarian and Slavic lords came to Aachen, in order to resolve mutual disputes in front of the Charlrmagne, thus reaffirming their submission to the supreme Frankish rule.

[20] In 817, new emperor Louis I (d. 840) decided to regulate (in advance) various issues related to succession, including the question of governance over dependent peoples on Frankish eastern frontiers.

When prince Louis finally became of age in 825–826,[22] those regions were still under administration of his older brother Lothar I (d. 855), ruler of Italy, and his frontier commander, duke Baldric of Friuli.

Very soon, he got the chance to achieve that goal, and concentrate in his hands governance over Bavaria and Carantania, including all eastern and southeastern marches and dependent Avarian and Slavic territories.