Belgium–Germany border

From Vienna to Versailles

The Congress of Vienna in 1815 treated the line between Prussia and the Low Countries as the “historical” boundary, and it was marked the next year; Belgium only split from the Netherlands later, in 1839. The Treaty of Versailles of 28 June 1919 gave Belgium Eupen-Malmedy and Moresnet, about 1,036 km² with 60,000 inhabitants.^[1]

On 23 May 1940 Nazi Germany reannexed Eupen-Malmedy and Moresnet by decree. The decree lapsed with the war’s end and the land went back to Belgium.^[1]

The Vennbahn and its exclaves

The Vennbahn railway ran south from Aachen. When Eupen and Malmedy became Belgian, an international commission decided on 27 March 1920 that the line should go with them, to protests in Monschau. In 1921 Belgium took over the track bed north to Raeren and south of Kalterherberg, creating a Belgian corridor 28.5 km long through German land.^[2]

About 55 km² of Germany west of the tracks was cut off, leaving five German exclaves: Rückschlag, Mützenich and Ruitzhof, which are whole places, and parts of Lammersdorf and Roetgen. Rückschlag, at 1.5 hectares with a single house, is Germany’s smallest exclave. A treaty signed at Aachen on 6 November 1922 set the rules, such as keeping German as the language of the line.^[2]

Provisional changes, then a treaty

In 1949 the occupying powers put seven small areas of West Germany, 20 km² with 500 people, under provisional Belgian administration. The two countries settled them by a treaty signed in Brussels on 24 September 1956. Most were returned to Germany, but Belgium kept the road south from Fringshaus to Konzen, the Elsenborn salient and part of the forest at Losheim. The changes took effect on 10 September 1958.^[1]