Having lost much popularity, the emperor inaugurated a more liberal domestic policy, widening the powers of the legislative assembly and lifting many restrictions on civil liberties. During the "Liberal Empire" (1860–70) such opposition leaders as Jules Favre, Émile Ollivier, and Adolphe Thiers were outstanding figures. A commercial treaty (1860) with Great Britain opened France to free trade and improved Franco-British relations. Imperialistic expansion was pushed by the French-British expedition (1857–60) against China, the acquisition of Cochin China, and the construction of the Suez Canal. Less fortunate was Napoleon's intervention (1861–67) in the affairs of Mexico; the French troops finally withdrew upon the demand of the United States, leaving Emperor Maximilian to his fate.
Napoleon remained neutral in the Austro-Prussian War of 1866, underestimating Prussian strength. The rise of Prussia under the leadership of Otto von Bismarck revealed a new rival for European power. To regain prestige Napoleon, at the behest of advisers, took an aggressive stand regarding the candidature of a Hohenzollern prince to the Spanish throne. This gave Bismarck the opportunity to goad Napoleon into war (see Ems dispatch).
The Franco-Prussian War (1870–71) brought ruin to the Second Empire. Napoleon himself took the field, leaving his empress, Eugénie, as regent, but he early devolved his command to Achille Bazaine. He was caught in the disaster of Sedan (Sept. 1, 1870), captured by the Prussians, and declared deposed (Sept. 4) by a bloodless revolution in Paris. Released after the armistice (1871), he went into exile in England, bearing defeat with remarkable dignity. His only son, the prince imperial (see under Bonaparte, family), was killed while serving in the British army.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.