Which 806 charter set terms for Charlemagne's succession?

The Divisio Regnorum was the 806 charter that set out Charlemagne's succession plan. The document divided his territories among his three legitimate sons: Charles the Younger, Pepin of Italy, and Louis the Pious, while also laying down rules intended to preserve peace among the heirs.

Charles the Younger was assigned Francia, Saxony, Nordgau, and parts of Alemannia. Pepin, already king in Italy, was to receive additional lands including most of Bavaria. Louis, king of Aquitaine, was designated to receive Provence, Septimania, and parts of Burgundy. The charter did not clearly settle inheritance of the imperial title itself.

The plan never took effect as intended. Pepin died in 810 and Charles the Younger died in 811, both before Charlemagne. With only Louis surviving, Charlemagne eventually made him co-emperor in 813, and Louis succeeded to the empire when Charlemagne died in 814.

The common mix-up is the Ordinatio Imperii of 817, issued by Louis the Pious. That later settlement emphasized imperial unity and differed from Charlemagne's 806 division plan.