Lotharingia was a historical region and an early medieval polity that existed during the late Carolingian and early Ottonian era, from the middle of the 9th to the middle of the 10th century. It was established in 855 by the Treaty of Prüm as a distinct kingdom within the Carolingian Empire, but abolished already in 869–870 when it was divided by the Treaty of Meerssen. It was territorially reunited in 880 by the Treaty of Ribemont, and reestablished as a kingdom from 895 to 900. Since 903 it was organized as a duchy, which existed up to 959 or 965, when it was divided into two distinct duchies: Upper Lotharingia, and Lower Lotharingia. Before the final division, the region comprised present-day Lorraine (France), Luxembourg, parts of Switzerland, parts of modern Germany west of the Rhine, most of Belgium, and the Netherlands.