The border shared by Luxembourg and Germany is recognized for its distinctive approach, as it is not defined by a traditional border line but by the joint governance of the Moselle, Sauer, and Our rivers. This arrangement, known as the German-Luxembourgish condominium, allows both nations to exercise shared sovereignty over the rivers, their islands, and specific bridges. This unique system dates back to the Congress of Vienna in 1815, a pivotal moment when European powers redrew territorial lines following the tumultuous Napoleonic Wars.
It was under Article 25 of the Final Act from the Congress of Vienna that these rivers were placed under collective ownership, rather than being split by a conventional median line. The initial agreements were further solidified by treaties signed in Aachen in 1816 between the Netherlands, which controlled Luxembourg at the time, and Prussia. As history unfolded, Luxembourg gained independence and Prussia evolved into part of the German Empire, yet the 19th-century agreements’ rights persisted, shaping the modern border shared by Germany and Luxembourg.
The shared sovereignty arrangement left the status of bridges that cross these rivers unresolved for over a century. However, with the canalisation of the Moselle, discussions took place in 1979 to address this ambiguity. The conclusion came with a border treaty in 1984, which officially extended the shared jurisdiction to include both bridges and footbridges over these waters.
Today, this condominium operates under a unique system of concurrent jurisdiction, where both German and Luxembourgish laws are applicable. Bilateral agreements are in place to manage any potential disputes effectively. Law enforcement agencies from both countries have the authority to operate within this shared territory, including the capability to conduct joint patrols. Officers from either nation can respond to offenses occurring on shared rivers or bridges, with jurisdiction over legal proceedings determined by factors like the individuals involved and the specific circumstances of each case.
This arrangement stands as a rare instance of shared sovereignty in Europe, presenting a distinctive border model that contrasts with the more typical boundaries seen between most nations. It highlights a cooperative approach to border management, enhancing cross-border relations between Germany and Luxembourg.