In the Italian War of 1859 he commanded the artillery, and by his action at the battle of Solferino materially assisted in achieving the victory. In September 1866, having in the meantime become aide-de-camp to Napoleon III, he was dispatched to Venetia to hand over that province to Victor Emmanuel. In 1869, on the death of Marshal Niel, General Leboeuf became minister of war, and earned public approbation by his vigorous reorganization of the War Office and the civil departments of the service. In the spring of 1870 he received the marshal's baton.