Tassilo III, Duke of Bavaria

K. L. Roper Pearson has suggested[5] that it probably represents a reworking of the original document by the annalist to emphasise Charlemagne's overlordship over Tassilo during the period of hostilities between the two rulers.

It is reported that Tassilo had gained such a reputation that he was regarded as a kingly ruler when his cousins Charles and Carloman assumed power in the Frankish realm in 768.

[9] In 788 Tassilo was accused by the Franks of defaulting on his military obligations to Pepin, leaving the Frankish campaign in Aquitaine on grounds of ill health way back in 763.

Whatever the motivations behind Tassilo's abandonment of the campaign, the Royal Frankish Annals for that year are particularly scathing of him, saying that he "brushed aside his oaths and all his promises and sneaked away on a wicked pretext".

[3] The incident was the linchpin in Charlemagne and Pope Adrian's argument that Tassilo was not an independent prince but a rebellious vassal, deserving punishment.

[10] The punishment was carried out, after much political maneuvering, during a diet in the Imperial Palace Ingelheim in 788, when Tassilo was finally deposed and then entered a monastery.