Marshal MacMahon had been struck by a splinter from a shell near Moncelle at 6 a.m. He had named General Ducrot as his successor in the chief command, passing over two senior Corps commanders. Apprized of this promotion at seven o'clock, that General issued the necessary orders for the prompt assemblage of the army at Illy, in preparation for an immediate retreat on Mezieres. He had already despatched Lartigue's Division of his own Corps to safeguard the crossing of the Givonne ravine at Daigny; the Divisions of Lacretelle and Bassoigne were ordered to take the offensive against the Saxons and Bavarians, to gain time for the withdrawal of the rest of the troops. The divisions forming the second line were to start immediately in a northerly direction. But the Minister of War had appointed General de Wimpffen, recently returned from Algiers, to the command of the Vth Corps in room of General de Failly, and had at the same time given him a commission empowering him to assume the command of the Army in case of the disability of the Marshal. General de Wimpffen knew the army of the Crown Prince to be in the neighbourhood of Donchery. He regarded the retreat to Mezieres as utterly impracticable, and was bent on the diametrically opposite course of breaking out to Carignan, not doubting that he could drive aside the Bavarians and Saxons, and so succeed in effecting a junction with Marshal Bazaine. When he heard of the orders just issued by General Ducrot, and at the same time observed that an assault on Moncelle seemed to be taking an auspicious course, he produced--to his ruin--the authoritative commission which had been bestowed on him. General Ducrot submitted without any remonstrance; he might probably not have been averse to be relieved of so heavy a responsibility. The Divisions of the second line which were in the act of starting immediately were recalled; and the further advance of the weak Bavarian and Saxon detachments was soon hard pressed by the impact of the first stroke of the enemy rushing on to the attack. By seven in the morning, while one regiment of the Saxon advanced guard had gone in upon Moncelle, the other on its right had to concern itself with the threatening advance of Lartigue's Division. With that body it soon became engaged in a heavy fire-fight. The regiment had laid down its packs on the march, and had omitted to take out the cartridges carried in them. Thus it soon ran short of ammunition, and the repeated and violent onslaughts of the Zouaves, directed principally against its unprotected right flank, had to be repulsed with the bayonet.