During the night of 7 July, a strong French advance guard crossed the river Weser close to the town Beverungen. While the river Weser normally cannot easily be forded, during the summer the water level drops down to a low of 80 cm (~3 feet) between Münden and Hameln, making it possible for infantry and cavalry to cross. The French advance troops then marched to the north and established a bridgehead at Höxter. The main army crossed the Weser on 16 July, leaving the Duke of Cumberland no choice but to deploy his troops south of Hamelin and to engage d'Estrées. The Prussian battalions were then recalled by Frederick the Great, after losing the Battle of Kolin against Austria.