As soon as it was realized that the unexpected Belgian resistance had retarded the German advance and in all probability had disarranged the German plan of campaign, the French, even before the guns of Liege had cooled, struck at Alsace, through the Belford Gap and over the Vosges Mountains. At first this French offensive was successful. Points on the Metz-Strassburg Railroad were taken and the town of Muelhausen captured. But almost before the news of success reached Paris the French had been defeated, not only in Alsace but also in Lorraine, whence French troops had been sent to engage the German Army of the Moselle. The result was the retirement of the French to the line of their first defense--a line that had been prepared for just such an emergency during the years since 1871. While the German armies of the Moselle and of the Rhine were thus occupied in repelling the French advance the Army of the Meuse was forcing its way through Belgium. Throwing out a strong cavalry screen in its front, this army advanced through Tongres, St. Frond, Laugen, Haelen, and Terlemont, and finally confronted the Belgians on the line from Louvain to Namur. Fighting on this front filled almost a week, when the destruction of the fortifications of Namur forced the Belgians to fall back, pivoting on Louvain to the line from Louvain to Wavre, the last line in front of Brussels. On Aug. 20 the Belgians were defeated at Louvain and the Germans entered Brussels, the Belgian Government having previously retired to Antwerp. The first phase of the German advance was thus completed and the way to France was open. SECOND PHASE From the Fall of Brussels to von Kluck's Retreat to the Aisne Immediately following the fall of Namur, which forced the Belgians to take up the Louvain-Wavre line, the main German Army of the Meuse started for France, leaving possibly two army corps to drive the Belgians from Brussels and to protect their flank and their lines of communication. The German advance first came in contact with the French and British along a line from Mons to Charleroi, southwest of Brussels. The British were supposed to have been between two French armies, but for some reason the army which had been assigned to position on the British left did not appear. Being outflanked, a retreat followed, the French being defeated at the same time at Charleroi. The German Army of the Moselle then attacked along the Meuse, and, being also successful, was on the flank and rear of the British and French retreating from Mons and Charleroi. Thus a great enveloping movement was disclosed which for some days gave every evidence of being successful. It was defeated, however, entirely by the British, who, though outflanked and outnumbered three to one, fought steadily night and day for six days, their small force holding in complete check all of von Kluck's army corps. Retreat was of course inevitable, but the retreat was made in good order and with the morale of the troops unshaken.