Complex sentence: Dissenters attempted a coup against Charlemagne at Tassilo's old capital of Regensburg in 792, led by his own son Pépin the Hunchback, and the king had to drag Tassilo out of imprisonment to formally renounce his rights and titles at the Assembly of Frankfurt in 794.
Split into simpler sentences: Dissenters attempted a coup against Charlemagne at Tassilo's old capital of Regensburg in 792, led by his own son Pépin the Hunchback. The king had to drag Tassilo out of imprisonment to formally renounce his rights and titles at the Assembly of Frankfurt in 794.