The French declared war before their troops were in position to invade Germany. The Germans, commanded by Field Marshal von Moltke, began to assemble into three armies, which were to invade France and to occupy Paris. On 4 August they crossed the frontier, where 3rd Army conquered the walled city of Wissembourg, Two days later they defeated the French again at Wörth. On the same day 2nd Army was marching westward, even though one of it corps was still on the railroad.