Taking up first the German right: It did not begin its real advance until August 12, 1914. Liege had been captured on August 7, the last fort fell on August 15. Meantime the Germans pushed a heavy screen of cavalry forward, and there was steady skirmishing between Liege and Brussels, which was magnified into battles and German defeats. In point of fact, the Belgian army was rapidly pushed back, and once the main German advance began, it fled to Antwerp. Kluck took Brussels on August 18, 1914, and turned south, meeting the first serious resistance at Mons. Buelow, moving across the Meuse at Huy, took Namur on August 23, 1914, and his troops fought at Charleroi, while those of Hausen forced a passage of the Meuse south of Namur. The French were beaten at Charleroi, and the British while the battle of Mons was still undecided, were forced to retreat, because Buelow's success in taking Namur had imperiled the whole allied left flank. Because he delayed his retreat too long, Sir John French was immediately threatened with destruction, Kluck having succeeded in getting on his flank, while sending superior numbers against his front. For a week there was grave danger that the Germans would be able to destroy the British and intervene between the French left and the city of Paris. At Cambrai on the 25th, British destruction seemed imminent, but the British just managed to win clear, and French troops coming up on their exposed flank by September 1, they were safe. The French center had essayed an offensive into the Ardennes at the moment the battle of Charleroi was beginning. In this they did not succeed, and the Fourth Army under Langle de Cary fell back in perfect order from the Belgian-Luxemberg frontier across the Meuse near Sedan, where they held their line until the general retreat began. Henceforth the French armies from left to right were not seriously threatened until the final struggle at the Marne. But the right under De Castelnau had been obliged to retreat. It had opened the campaign by a series of victories which had carried the main force into German Lorraine as far as Saarburg on the railroad from Metz to Strassburg. To the south Muelhausen had been taken, lost, and recaptured. But in the third week of August the main army encountered strong forces in the region of Morhange and fell back on Nancy, the frontier town of Luneville being momentarily occupied by the Germans. At Nancy it stood. But its stand was one of the important battles of the western war and a contributory cause to the subsequent victory at the Marne. By this victory the eastern barrier was held and the German effort to isolate Verdun and Toul blocked. Some of the most terrible fighting of the war took place here, and the Germans, fighting under the eye of the kaiser suffered colossal losses.