Louis the Pious, Succession Crises, and the Treaty of Verdun (843)

Louis the Pious succeeded his father Charlemagne in 814 as his only surviving son, initially continuing his father's policies of religious and cultural reform. In 817 he promulgated the Ordinatio Imperii, a plan for unified succession that named Lothair I as co-emperor while assigning subordinate kingdoms to Pippin of Aquitaine and Louis the German. The birth of Charles the Bald in 823, from Louis's second marriage to Judith of Bavaria, introduced new pressure, as Judith pushed to have Charles included in the succession. This broke the original Ordinatio Imperii settlement and triggered the first rebellions of Louis's elder sons in 830.