Born Jan. 12, 1809, in Santa Cruz de Tenerife; died Nov. 5, 1867, in Biarritz. Spanish general and politician. Count of Lucena (from 1839), duke of Tétouan (from 1860).

The son of a high government official and general, O’Donnell fought against the Carlists in the First Carlist War of 1833–40 and, after B. Espartero of the liberal-bourgeois progresista party assumed power in 1840, emigrated to France. In 1841 he participated in an unsuccessfull rising against Espartero in Pamplona and then emigrated again, but he returned to Spain in 1843 after Espartero’s fall. O’Donnell served as captain general of Cuba from 1844 to 1848.

On July 7, 1854, O’Donnell issued the Program of Manzanares, which formulated the demands of the liberal bourgeoisie in the Spanish revolution of 1854–56. He formed a temporary alliance with Espartero and joined the government headed by the latter, although he stood politically to the right of Espartero. In late 1854, O’Donnell assumed the leadership of the Liberal Union, the party of the right-wing Liberals. He then planned the counterrevolutionary coup d’etat of 1856. After Espartero’s resignation, O’Donnell was prime minister, alternating with R. M. Narváez, in 1856, 1858–63, and 1865–66.

As prime minister, O’Donnell disbanded the national militia that was created during the revolution, legalized the Jesuits, who had been outlawed since 1835, and suppressed a peasant movement in Andalusia in 1861. During the Spanish-Moroccan War of 1859–60, O’Donnell commanded the Spanish troops operating in Morocco. In 1861 he concluded an agreement with the governments of Great Britain and France on joint Anglo-French-Spanish military intervention in Mexico.