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Lothair I ruled Italy from 818 to 855. He was the eldest son of Emperor Louis the Pious and his first wife, Irmingard of Hesbaye. In 818, Lothair was crowned co-emperor with his father. After Louis' death in 840, Lothair inherited Italy, Provence, Burgundy, and Lotharingia. He also received the title of Holy Roman Emperor. Lothair's reign was marked by political instability and civil war.