Treaties of Nijmegen
From 1648 to 1660 Longwy was part of the Kingdom of France, returning to the Duchy of Lorraine afterwards. It was made part of France again in 1670, a situation which was finalized in the Treaties of Nijmegen in 1678. Vauban fortified the town during the reign of Louis XIV, having demolished the medieval Château de Longwy, of which one tower remains.