Treaty of Ribemont
There are two Treaties of Ribemont, the first is from 880 and the second is from 1179.
The treaty of 880
The Treaty of Ribemont in 880 was the last treaty on the partitions of the Frankish Empire. It was signed by the German king Louis the Younger and the kings of Western Francia, Louis III and Carloman.
After the death of Charles the Bald, Louis the Younger secured the friendship of Charles' successor Louis the Stammerer with the Treaty of Fourons in November 878. The two nephews promised to accept the successions of their respective sons. The treaty was put to the test when Louis the Stammerer died in April 879. A western delegation led by Gauzlin, bishop of Paris and later protector of the city during the Viking raids, invited Louis the Younger to take control of West Francia. Because his wife Luitgard also supported this idea, Louis the Younger invaded West Francia. He reached as far as Verdun, but he retreated after his nephews, the kings Louis III of France and Carloman of France, gave up their share of Lotharingia to him.
Meanwhile Boso of Provence, a noble of Carolingian descent, proclaimed himself king of the Provence. Moreover, the Vikings resumed their attacks. To deal with these threats, the Carolingian kings decided to put aside their differences so as to deal with the threats together. They met at Ribemont, in present day Aisne. In return for Louis the Younger's neutrality, the kings of France confirmed Louis' possession of the parts of Lotharingia that had been given to him since the Treaty of Meerssen. This left them free to deal with Boso.
The border between France and the Holy Roman Empire remained largely the same until the Late Medieval.
Earlier Frankish partitions were:
The treaty of 1179
The second treaty was signed on 2 may, 1179, by the descendants of Duke Matthias I, Duke of Lorraine. Matthias had died in 1176, and the duchy was claimed by both his eldest son Simon II, Duke of Lorraine and his second eldest son Frederick I, Duke of Lorraine. The two brothers fought a three-year long war, before they decided to partition the Duchy in Ribemont; Simon received the southern French-speaking part of the duchy, and Ferry received the northern German-speaking part. In 1206 the duchy was united once more by Frederick II, Duke of Lorraine.