No sooner had Brunswick been brought to a stand by Dumouriez at Valmy than a French division under Custine crossed the Alsatian frontier and advanced upon Spires, where Brunswick had left large stores of war. The garrison was defeated in an encounter outside the town; Spires and Worms surrendered to Custine. In the neighbouring fortress of Mainz, the key to Western Germany, Custine's advance was watched by a republican party among the inhabitants, from whom the French general learnt that he had only to appear before the city to become its master. Brunswick had indeed apprehended the failure of his invasion of France, but he had never given a thought to the defence of Germany; and, although the King of Prussia had been warned of the defenceless state of Mainz, no steps had been taken beyond the payment of a sum of money for the repair of the fortifications, which money the Archbishop expended in the purchase of a wood belonging to himself and the erection of a timber patchwork. On news arriving of the capture of Spires, the Archbishop fled, leaving the administration to the Dean, the Chancellor, and the Commandant. The Chancellor made a speech, calling upon his "beloved brethren" the citizens to defend themselves to the last extremity, and daily announced the overthrow of Dumouriez and the approaching entry of the Allies into Paris, until Custine's soldiers actually came into sight. [21] Then a council of war declared the city to be untenable; and before Custine had brought up a single siege-gun the garrison capitulated, and the French were welcomed into Mainz by the partisans of the Republic (Oct. 20). With the French arms came the French organisation of liberty. A club was formed on the model of the Jacobin Club of Paris; existing officers and distinctions of rank were abolished; and although the mass of the inhabitants held aloof, a Republic was finally proclaimed, and incorporated with the Republic of France. [Dumouriez invades the Netherlands.] [Battle of Jemappes, Nov. 6.]