1870: When the French emperor, Napoleon III, demanded territories of the Rhineland in return for his neutrality amid the Austro-Prussian War, Bismarck used the Spanish Succession Question (1868) and Ems Telegram (1870) as an opportunity to incorporate the southern kingdoms. Napoleon III declared war against Prussia. 1871: The Franco-Prussian War ended with Prussian troops capturing Paris, the capital of the Second French Empire.