Napoleon III (1808-1873). 1874 illustration of the first President of France (1848 to 1852) and last French monarch (1852 to 1870) Charles Louis Napoleon Bonaparte (Napoleon III). Napoleon III was first elected president of the French Second Republic in 1848. When he could not constitutionally be re-elected, he seized power in 1851 and became the Emperor of the French. He founded the Second French Empire and was its only emperor until the defeat of the French army and his capture by Prussia and its allies in the Franco-Prussian War in 1870.