Lothair II was a Holy Roman Emperor who reigned from 855 to 869. He was the son of Lothair I and Ermengarde of Tours. Lothair II is best known for his attempts to maintain control over the territories of the empire, which were often divided among his brothers. His reign was marked by conflicts and power struggles, particularly with his siblings. During his rule, Lothair II faced challenges from both internal factions and external threats. He was involved in the Treaty of Meerssen in 870, which aimed to resolve disputes over land and power among the Carolingian rulers. Lothair II's reign ultimately ended with his death in 869, leading to further fragmentation of the empire.