In Europe, the border shared by Luxembourg and Germany along the Moselle, Sauer, and Our rivers presents a unique arrangement. Unlike typical border demarcations, these rivers and their features are managed under joint sovereignty by both nations, a system known as the German-Luxembourgish condominium. This unusual governance dates back to the early 19th century, specifically the Congress of Vienna in 1815, when European borders were redefined following the Napoleonic Wars.
The Congress of Vienna’s Final Act, particularly Article 25, established that these rivers would be jointly owned rather than split by a conventional median line. This arrangement was solidified by subsequent treaties signed in Aachen in 1816 between the Netherlands, which ruled Luxembourg at that time, and Prussia. Even as Luxembourg gained independence and Prussia was absorbed into the German Empire, the agreements from the 19th century held firm, shaping the current German-Luxembourgish border.
For over a century, the status of the bridges spanning these shared rivers remained an unresolved issue. However, with the canalisation of the Moselle came renewed negotiations, culminating in a border treaty in 1984. This treaty formally included bridges and footbridges in the shared territory, providing clarity to the condominium’s jurisdiction.
Today, this shared sovereignty is managed through concurrent jurisdiction, allowing both German and Luxembourgish laws to be applicable in the area. Bilateral agreements help in addressing any potential legal conflicts. Police forces from both countries are authorized to operate in the shared space, conducting joint patrols and intervening in incidents occurring on the rivers or bridges. The jurisdiction for subsequent legal proceedings often depends on the individuals involved and the specifics of the incident.
This arrangement remains a rare example of collaborative sovereignty in Europe, distinguishing the German-Luxembourgish border from conventional national boundaries. It represents a cooperative approach to border management that continues to function effectively, ensuring that both nations can operate seamlessly within this shared territory.