While great part of the allied army remained in cantonments about Munster, the French armies on the Upper and Lower Rhine, being put in motion, joined on the third day of June near Marburgh, under the command of the mareschal de Contades, who advanced to the northward, and fixed his head-quarters at Corbach, from whence he detached a body of light troops to take possession of Cassel, which, at his approach, was abandoned by general Imhoff. The French army being encamped at Stadtberg, the duke de Broglio, who commanded the right wing, advanced from Cassel into the territories of Hanover, where he occupied Gottin-gen without opposition; while the allied army assembled in the neighbourhood of Lipstadt, and encamped about Soest and Werle. Prince Ferdinand, finding himself inferior to the united forces of the enemy, was obliged to retire as they advanced, after having left strong garrisons in Lipstadt, Retberg, Munster, and Minden. These precautions, however, seemed to produce little effect in his favour. Retberg was surprised by the duke de Broglio, who likewise took Minden by assault, and made general Zastrow, with his garrison of fifteen hundred men, prisoners of war, a misfortune considerably aggravated by the loss of an immense magazine of hay and corn, which fell into the hands of the enemy. They likewise made themselves masters of Munster, invested Lipstadt, and all their operations were hitherto crowned with success. The regency of Hanover, alarmed at their progress, resolved to provide for the worst, by sending their chancery and most valuable effects to Stade, from whence, in case of necessity, they might be conveyed by sea to England.
In the meantime they exerted all their industry in pressing men for recruiting and reinforcing the army under prince Ferdinand, who still continued to retire; and on the eleventh day of July removed his headquarters from Osnabruck to Bompte, near the Weser. Here having received advice that Minden was taken by the French, he sent forward a detachment to secure the post of Soltznau on that river, where on the fifteenth he encamped.