(Sept. 1, 1870) Defeat of the French army in the Franco-Prussian War that led to the fall of the Second Empire .
At the French border fortress of Sedan on the Meuse River, 120,000 French troops under Maurice, count de Helmuth von Moltke . After Mac-Mahon was wounded, the confused French command tried unsuccessfully to break through the encircling German lines with massive cavalry charges. Emperor {{link=Napoleon">Napoleon III , who had accompanied Mac-Mahon, realized the French position was hopeless and surrendered with 83,000 troops.