Work began on in 1852.
He expanded the and made the French merchant navy the second largest in the world, engaged in the as well as the disastrous , in which he commanded his soldiers during the fight and was captured.
In July 1858, Napoleon arranged a secret visit by Count Cavour.
The Germans suffered 20,000 casualties and the French 12,000, but the Germans emerged as the victors, as Marshal Bazaine's army, with 175,000 soldiers, six divisions of cavalry and five hundred cannons, was trapped inside the fortifications of Metz, unable to move.
Leopold resisted the idea, but finally agreed on the 11th, and the withdrawal of the candidacy was announced on the 12th, a diplomatic victory for Napoleon.
France was forced to renounce any claim to Luxembourg in the.