It was now two o'clock. So far General von Alvensleben had deceived the enemy with regard to the slenderness of his force by acting incessantly on the offensive. But the battle was now at a standstill, the battalions were visibly thinned, their strength was sapped by four hours of hard fighting, and the ammunition of the infantry was almost exhausted. Not a battalion, not a battery remained in reserve behind the fighting line standing there in the fire. It was now required to conserve the success won with so much blood by acting thenceforth on the defensive. The left wing was in especial danger, being under the fire of the powerful artillery deployed on the Roman road. Their greatly superior numbers enabled the French to extend farther and farther to the right, threatening thus completely to envelop the Prussian flank. Marshal Canrobert, in the French centre, had discerned the right moment to press forward against Vionville with all his might. At this critical instant there was on the German side only a small detachment of the 5th Cavalry Division available to check this effort. Two brigades had necessarily been sent to strengthen the left flank, and of the 12th Brigade remaining in rear of Vionville two squadrons had been detached to the Tronville copses. The two regiments ordered to undertake the task of charging the advancing enemy--the Magdeburg Cuirassiers and the Altmark Uhlans--were consequently each but three squadrons strong, in all 800 horses. General von Bredow, commanding the 12th Cavalry Brigade, first traversed in column the shallow hollow sinking down from Vionville, then wheeled to the right and mounted the slope to the eastward, both his regiments on one front. Received immediately with heavy artillery and infantry fire, he threw himself on the hostile ranks. The first line is ridden over, the line of guns is broken through, gunners and teams are put to the sword. The second French line is powerless to resist this vigorous onslaught, and even the more distant batteries limbered up to drive away. But the rapture of victory and the impetuosity of the charge carried the handful of troopers too far, and after a gallop of 3000 paces they found themselves surrounded by the French cavalry, which attacked them from all sides. There was no scope for a second charge, and so after several encounters with the French horse the brigade was forced to cut its way back through the French infantry, whose bullets accompanied it home. Only one-half of the command returned to Flavigny, where it was reorganized into two squadrons. The devoted self-sacrifice of the two heroic regiments effected the result, that the French entirely discontinued their attack on Vionville.