Napoleon III was the first president of France from 1848 to 1852 and the emperor of the French from 1852 to 1870. A nephew of Napoleon I, he was the last monarch to reign over France. Elected to the presidency of the Second Republic in 1848, he seized power by force in 1851, when he could not constitutionally be reelected; he later proclaimed himself Emperor of the French. He founded the Second Empire, reigning until the defeat of the French Army and his capture by Prussia and its allies at the Battle of Sedan in 1870. Napoleon III was a popular monarch, who used plebiscites to guide his actions, oversaw the modernisation of the French economy and worked to have the centre of Paris rebuilt following Napoleon III style guidelines. He expanded the French overseas empire and made the French merchant navy the second largest in the world, engaged in the Second Italian War of Independence as well as the disastrous Franco-Prussian War, in which he commanded his soldiers during the fight and was captured.