Treaties of Nijmegen
In the mediaeval period the Wissembourg Gap was an internal border within the Holy Roman Empire, marking the boundary between the County Palatine of the Rhine to the north and the Alsatian Décapole (), a federation of ten cities including Wissembourg, to the south. Under the 1679 Treaties of Nijmegen the Décapole was annexed by Louis XIV of France, and the Wissembourg Gap therefore became an international border between the Holy Roman Empire and the Kingdom of France.