The main blow at France was to come through Belgium. Five German armies out of eight were hurled against this gateway to Northern France. In Lorraine and Alsace the Germans were temporarily to remain on the defensive. The protection of Lorraine was intrusted to the Bavarian (Sixth) Army, that of Alsace to the remaining two armies. The French plan of operation was to check the invasion of Belgium on the line Tongres-Liege-Longwy, where the Belgian Army, from a strictly military point of view, forming the advance guards of the French Army of the North, was holding strong positions, and with superior forces to strike at the German Army of Lorraine. The aim was, avoiding Metz, to reach the Moselle near Trier through the valley of the Saar, and to roll up the German Army of the North from its left wing. An invasion of Alsace was merely to satisfy political aspirations. The German advance in Belgium, however, remained unchecked, and in Lorraine the battles of Dieuze and Saarbourg on Aug. 20 decided the issue in favor of the Bavarians. In Alsace the French were victorious over the Eighth Army and took Muelhausen, while further north, between Muenster and Shirmeck, the Seventh Army checked the French invasion. Meanwhile the German avalanche in Belgium had reached the second line of defense, Brussels-Namur-Longwy, before the French Army of the North. The capture of Namur prompted the French staff to recall advance guards, which had reached the fortress just as it surrendered, and to accept battle in the line Mons-Charleroi-Givet-Longwy. The battle for the invasion of France and the retirement of the French armies in all the theatres of action which it caused opens the second period of the campaign against France. The English contingent from Havre had joined the French Army just before the German onslaught began. The battle was lost by the Allies tactically and strategically through the defeat of their right wing at Longwy and Neufchateau, and through the encircling of their left wing at Mons. The direct result of the outcome was the German invasion of France; the indirect consequence (resulting from the necessity of drawing troops from the other fields of action to stem the German invasion) was the retirement of the French armies in Lorraine and Alsace to the line Verdun-Nancy-St. Die, and further south to the passes of the Vosges, which they have been holding ever since. Sweeping on through Northern France, the German Army of the North was breaking up all resistance in its path, such as was attempted by the British at St. Quentin on Aug. 28, and was tearing with it all fortresses, such as Longwy, La Fere, Maubeuge, and others; but it was failing in its principal aim: to embrace the skillfully retreating enemy before he could reach the line Paris-Verdun, which he had selected and prepared for the next stand.