Which Bavarian duke was deposed by Charlemagne in 788?

Tassilo III was the Bavarian duke deposed by Charlemagne in 788.

Tassilo belonged to the Agilolfing dynasty and had ruled Bavaria since 748, initially under the overlordship of Charlemagne’s father, Pepin the Short. His position was unusually important because Bavaria occupied a strategic region between the Frankish kingdom and the peoples of central and southeastern Europe.

Relations deteriorated as Tassilo tried to preserve Bavarian autonomy. The Franks accused him of failing to provide military service and of acting disloyally toward the Carolingian rulers. Charlemagne summoned him to the imperial palace at Ingelheim in 788, where Tassilo was condemned and removed from power.

Tassilo entered a monastery, but his family’s claims were not immediately forgotten. At the Synod of Frankfurt in 794, he was compelled to renounce his rights to Bavaria formally. Bavaria was then incorporated more directly into Charlemagne’s realm. Odilo, one of the wrong options, was Tassilo’s father; Grifo was an earlier challenger for the Bavarian duchy.