insane king of Bavaria, younger son of King Maximilian II.

Otto fell insane in 1872 and, from 1880 onward, had to be kept under strict surveillance. When his elder brother, King Louis II, likewise insane, died in 1886, he became king under the regency first of his uncle Luitpold, the heir apparent, and then (1912) of Luitpold's son Louis, who made himself king, as Louis III, on Nov. 5, 1913, even though his cousin Otto was still alive.

The second son of King Louis I of Bavaria, Otto was chosen king of Greece by the great powers at the conference of London in May 1832. The Greek National Assembly confirmed his selection in August 1832, and he arrived in Greece on Feb. 6, 1833, accompanied by several Bavarian advisers. He instituted a new legal code and organized a regular army, but the Bavarians' absolutist rule and heavy taxation led to discontent, which was appeased by the resignation of Otto's chancellor, Joseph Ludwig von Armansperg, in 1837. After failing to annex Crete in 1841, an attempt that alienated Great Britain, the Greeks staged a revolt in 1843. Otto, a Roman Catholic in an Eastern Orthodox country, was forced to grant a constitution specifying that his eventual successor be Orthodox. A Greek oligarchy now replaced the former Bavarian one. The King toyed with the “Great Idea,” the reestablishment of the former Byzantine Empire with its capital at Constantinople; but his intervention against Turkey in the Crimean War (1853–56) merely provoked a Franco-British occupation of the Piraeus, and he failed to gain any additional territory for Greece. Otto's backing of Austria in the Italian War of Independence (1859) further damaged his prestige. He was finally deposed in a revolt on Oct. 23, 1862, and returned to Bavaria.