He was one of the superior military authorities who in this period 1866-1870 foresaw and endeavoured to prepare for the inevitable war with Germany, and at the outbreak of the Franco-Prussian War he was given by Napoleon the choice between a corps command and the post of chief engineer at headquarters. He chose the command of the II corps. On 6 August 1870 he held the position of Spicheren against the Germans until the arrival of reinforcements for the latter and the non-appearance of the other French corps compelled him to retire. After this he took part in the battles around Metz, where he distinguished himself at Mars-la-Tour and Gravelotte. He then participated with his corps in the Siege of Metz and was involved in the surrender of Bazaine's army. General Frossard published in 1872 a "Rapport sur les operations du 2 corps". He died at Cháteau-Villain (Haute-Marne).