Key Facts
- Established
- 855 AD by Treaty of Prüm
- Duration
- 855–959/965 AD (~110 years)
- Named after
- King Lothair II, its first ruler
- Final division
- Split into Upper and Lower Lotharingia (959–965)
- Modern territories covered
- Lorraine, Luxembourg, Belgium, Netherlands, parts of Germany and Switzerland
Imperial Zenith Metrics
Historical Trajectory
Phase I: Rise
Lotharingia was created in 855 by the Treaty of Prüm when the Carolingian ruler Lothair I divided his realm among his sons, granting the central strip—stretching from the Low Countries to northern Italy—to Lothair II. This territory encompassed the ancient Frankish core of Austrasia and became a distinct kingdom within the broader Carolingian framework, reflecting the ongoing fragmentation of Charlemagne's unified empire among competing dynastic heirs.
Phase II: Zenith
At its greatest coherence, Lotharingia controlled a strategically vital corridor between East and West Francia, encompassing present-day Lorraine, Luxembourg, most of Belgium, the Netherlands, and western German lands. Its position over the old Frankish heartlands made it a prize of immense symbolic importance, as both East and West Frankish rulers regarded possession of Austrasia as legitimizing their claim to the Carolingian imperial legacy.
Phase III: Decline
After Lothair II died without legitimate heirs in 869, his uncles divided Lotharingia by the Treaty of Meerssen. It was briefly reunified under Carolingian rule from 880 and reestablished as a kingdom (895–900), before being reorganized as a duchy under East Frankish and then Ottonian authority. By 959–965 it was definitively divided into Upper Lotharingia (Lorraine) and Lower Lotharingia, ending its existence as a unified polity.
Notable Imperial Reigns
Selected rulers mapping the empire’s trajectory