relinquishment of office by a sovereign or other ruler. In modern times, sovereigns have abdicated for many different reasons.

Queen Christina of Sweden relinquished her crown in 1654 because she was weary of the cares of office. Ill health caused the abdication of the Holy Roman emperor Charles V in 1558 and of King Philip V of Spain in 1724. Louis Bonaparte, appointed (1806) king of Holland by Napoleon, abdicated in 1810 in protest because his brother, at that time the emperor of France, treated Holland as merely a province of France. King Charles Emmanuel IV of Sardinia (1751–1819) was compelled by the French government to abdicate in 1802; his brother and successor, King Victor Emmanuel I, abdicated in 1821 in the face of a popular uprising against his regime. Foreign force compelled the abdications of the Polish kings Augustus II the Strong (1670–1733, deposed 1704, abdicated 1706), Stanislas I Leszczynski (1735), and Stanislas II Augustus (1795) and of Charles IV of Spain (1808). Napoleon also was forced to abdicate by allied foreign powers, both in 1814 and, after his return, in 1815 (see Napoleonic Wars: Defeat of Napoleon).

Insurrections often have forced abdications, including those of Richard II of England (1399), Mary, queen of Scots (1567), Charles X of France (1830), Louis Philippe of France (1848), Ferdinand I of Austria (1848), Louis I of Bavaria (1848), King Charles Albert of Sardinia-Piedmont (1798–1849, abdicated 1849), King Amadeus of Spain (1845–90, abdicated 1873), Prince Alexander I of Bulgaria (1857–93, abdicated 1886), King Milan of Serbia (1854–1901, abdicated 1889), Manuel II of Portugal (1910), and Nicholas II of Russia (1917).

The defeat of the Central Powers in World War I resulted (1918) in a number of abdications, including those of William II of Germany, Charles I of Austria-Hungary, Louis III of Bavaria (1845–1921), King Frederick Augustus III of Saxony (1865–1932), and William II of Württemberg. Several more abdications occurred between World War I and World War II. King Constantine I of Greece was forced to abdicate twice: by foreign and domestic political pressure in 1917, during World War I, and, after his recall, again in 1922 as a consequence of the Greek defeat in the Turkish War. King Prajadhipok (1893–1941) of Siam (now Thailand) abdicated in 1935 because of bad health. King Edward VIII of Great Britain (later duke of Windsor) abdicated in 1936 because the government opposed his marriage plans.

In 1940, during World War II, Germany forced King Carol II of Romania to abdicate. The Iranian ruler Riza Shah Pahlavi was allegedly an Axis sympathizer, so when Great Britain and the USSR occupied key areas of Iran in 1941 he abdicated in favor of his son, Muhammad Riza Shah. King Victor Emmanuel III of Italy abdicated in 1946 in favor of his son, Humbert II (1904–83). The Italians, however, voted to make Italy a republic, and Humbert was deposed in 1947. King Michael of Romania (1921–    ) abdicated in 1947 under the pressure of Romanian Communists.

Queen Wilhelmina of the Netherlands abdicated in 1948 because of ill health. Left-wing political pressures forced King Leopold III of Belgium to abdicate in favor of his son, Baudouin, in 1951. King Faruk I of Egypt had to abdicate in 1952 after a military coup d'état. King Norodom Sihanouk chose to abdicate the throne of Cambodia in 1955 in protest against internal opposition to his pro-Western policies; he was restored to the throne in 1993. In 1980, at the age of 71, Queen Juliana of the Netherlands abdicated in favor of her daughter, Beatrix.