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 (Neustria) and Carloman (Aquitaine), gave up their share of Lotharingia to him.

They were aided by Louis the Younger and his brother, King Charles the Fat, who was ruling in Alamannia, Upper Burgundy and Italy.

The border between France and the Holy Roman Empire remained largely the same until the Late Middle Ages.