Luxembourg and Germany share a unique border arrangement, where the Moselle, Sauer, and Our rivers are managed through joint governance rather than being split by a conventional boundary line. This area, known as the German-Luxembourgish condominium, is under the shared sovereignty of both nations, encompassing the rivers, their islands, and specific bridges. The origin of this unusual collaboration dates back to 1815, following the Congress of Vienna, when European powers were realigning borders in the aftermath of the Napoleonic Wars.
The Congress of Vienna’s Final Act, specifically Article 25, stipulated that these rivers would be jointly owned instead of being divided by a typical median line. This decision was reinforced by treaties signed in Aachen in 1816, involving the Netherlands, which governed Luxembourg at the time, and Prussia. As Luxembourg gained independence and Prussia became part of the German Empire, the rights established in these 19th-century agreements persisted, ensuring the modern border between Germany and Luxembourg remains largely as it was then.
For over a century, the status of bridges spanning these shared rivers was ambiguous. However, after the Moselle was canalized, negotiations commenced in 1979 to clarify these uncertainties. This led to a 1984 border treaty that officially incorporated bridges and footbridges into the shared territory. Today, the condominium is administered through a concurrent jurisdiction system, allowing both German and Luxembourgish laws to apply, with bilateral agreements in place to address potential conflicts.
In this shared territory, police forces from both nations have the authority to operate, including conducting joint patrols. Officers from either country can respond to offenses occurring on the shared rivers or bridges, with jurisdiction over legal proceedings determined by factors such as the individuals involved and the specifics of the offense. This arrangement exemplifies a rare form of shared sovereignty in Europe, creating a distinctive border that operates differently from the standard boundaries between most nations.