Ten Days of JVar 77 west of the Meuse, its cavalry could operate via Brussels to the French frontier at Lille. Such was the conception of the Belgian opera- tion which all commentators before and since the war began have held. They foresaw that Germany might attempt to throw her main force upon the flank and rear of the French barrier forts of the Verdun- Belfort line. To German forces advancing from Southeast Belgium into France the sole natural barrier is the Meuse River from Verdun to Namur. Had the Germans succeeded in taking Namur they would have held both banks of the river and the French defensive would have been thrown back somewhere on the Verdun-Rheims-Laon line of de- fences far within French territory. Now consider what happened. Liege did not surrender, and instead of arriving at Namur on August 7 the Germans only succeeded in getting into Liege that night. Meantime Belgian troops had time to occupy Namur solidly and the line of the Meuse became a formidable obstacle to German ad- vance from the fortress of Verdun to that of Namur. French concentration on the south bank of the Meuse was made possible; in fact, French offensive opera- tions north of the Meuse toward Luxemburg were reported. What had happened at Liege after the Germans entered the town long remained a complete mystery. The best information available on August lo pointed to the prolongation of the battle by some of the forts