Treaty of Meerssen
The Transjurane duchy was then ruled by Hucbert, a scion of the Bosonid dynasty, the younger son of Count Boso the Elder of Arles, and through his sister Teutberga brother-in-law to King Lothair II. Hucbert, however, fell out of favour after Lothair II divorced Teutberga, was defeated at the Battle of Orbe in 864 and replaced by Count Conrad II of Auxerre from the Elder House of Welf (Rudolfings), who from 866 ruled Transjurania as a margrave. When Lothair II died without heirs in 869, his Lotharingian realm was divided into a West and East Frankish part between his uncles Charles the Bald and Louis the German by the 870 Treaty of Meerssen.