Lothair was born in 795, to Louis the Pious and Ermengarde of Hesbaye. His father was the son of the reigning Emperor, Charlemagne. Little is known of Lothair's early life, which was probably passed at the court of his grandfather Charlemagne. In 814, the elderly emperor died, and left his sole surviving legitimate son Louis the Pious as successor to his vast empire. The next year, Lothair would be sent to govern Bavaria for his father, the new emperor. In 817, Louis the Pious drew up his Ordinatio Imperii. In this, Louis designated Lothair as his principal heir and ordered that Lothair would be the overlord of Louis' younger sons Pippin of Aquitaine (who was 20) and Louis the German (who was 13), as well as his nephew (Lothair's cousin) Bernard of Italy. Lothair would also inherit their lands if they were to die childless. Lothair, aged 22, was then crowned joint emperor by his father at Aachen. At the same time, Aquitaine and Bavaria were granted to his brothers Pippin and Louis, respectively, as subsidiary kingdoms. Following the death of Bernard, brought on by his plotting against and blinding by Louis the Pious, Lothair also received the Kingdom of Italy. In 821, Lothair married Ermengarde (d. 851), daughter of Hugh the Count of Tours.
Lothair was born in 795 to Louis the Pious and Ermengarde of Hesbaye. His father was the son of the reigning Emperor, Charlemagne. Little is known of Lothair's early life, which was probably passed at the court of his grandfather Charlemagne. In 814, the elderly emperor died, and left his sole surviving legitimate son Louis the Pious as successor to his vast empire. The next year, Lothair would be sent to govern Bavaria for his father, the new emperor. In 817, Louis the Pious drew up his Ordinatio Imperii. In this, Louis designated Lothair as his principal heir and ordered that Lothair would be the overlord of Louis' younger sons Pippin of Aquitaine (who was 20) and Louis the German (who was 13), as well as his nephew (Lothair's cousin) Bernard of Italy. Lothair would also inherit their lands if they were to die childless. Lothair, aged 22, was then crowned joint emperor by his father at Aachen. At the same time, Aquitaine and Bavaria were granted to his brothers Pippin and Louis, respectively, as subsidiary kingdoms. Following the death of Bernard, brought on by his plotting against and blinding by Louis the Pious, Lothair also received the Kingdom of Italy. In 821, Lothair married Ermengarde (d. 851), daughter of Hugh the Count of Tours.