Treaties of Nijmegen
The war with the Dutch officially ended on 10 August 1678 with the signing of the Treaties of Nijmegen, although a combined Dutch-Spanish army attacked the French at Saint-Denis on 13 August. The agreement ensured Spain retained Mons and on 19 September, they signed their own treaty with France, ceding Saint-Omer, Cassel, Aire, Ypres, Cambrai, Valenciennes and Maubeuge. With the exception of Ypres, returned to Spain in 1697, this fixed France's northern frontier close to where it remains today but the Treaties of Nijmegen proved the highpoint of French expansion under Louis XIV.