Bazaine moved part of his corps forward, but only to "take up strong positions," not to strike a blow on the battlefield. Remaining in Metz was based on the knowledge that if the slow-moving French army ventured far out it would infallibly be headed off and brought to battle in the open by a superior numbered adversary. In "strong positions" close to his stronghold, however, Bazaine hoped that he could inflict damaging repulses on the German enemy. The over-cautious troop movement, to prevent surprise rushes and ambushes, reduced the mobility of a large army, which had favourable marching conditions, to 5 miles a day as against the enemy's rate of 15 miles a day. Bazaine attempted halfheartedly to begin a retreat on Verdun. In his book Episodes de la guerre de 1870 et le blocus de Metz, Bazaine retrospectively argues that Verdun was the best line of defense for France, and therefore Napolean was right in ordering a retreat to Verdun, after the defeats of August. However, the French staff work and organization of the movement over the Moselle was so ineffective that when the German staff calculated that Bazaine was nearing Verdun, the French had in reality barely got their artillery and baggage trains through the town of Metz. Even on the battlefield Bazaine forbade the general staff to appear, and conducted the fighting by means of his personal orderly officers. Mars-la-Tour A cavalry patrol of the 1st Squadron of the 1st Hanoverian Dragoon Regiment No. 9, led by Rittmeister Oskar von Blumenthal, discovered that Marshal François Bazaine's 160,000-man Army of the Rhine was attempting to escape from Metz to join with French forces at Verdun. This intelligence prompted General Prince Friedrich Karl, commander of the Prussian Second Army, to order at 1900 on 15 August a grossly outnumbered group of 30,000 men of the advanced III Corps under General Constantin von Alvensleben to cut off the French line of retreat at Mars-la-Tour and Vionville. Bazaine's army had passed through on its way to Metz, and was attacked by this isolated corps of the enemy near the village of Mars-la-Tour. Bazaine's was able to successful repel the attack in spite of the fierce fighting by the two German corps. However, Alvensleben defeated all attempts by four French corps to dislodge his III Corps. On 16 August, Alvensleben attacked the French advance guard, believing that it was the rearguard of