Ferdinand I, 1751–1825, king of the Two Sicilies (1816–25). He had previously been king of Naples (1759–99, 1799–1805, 1815–16) as Ferdinand IV and king of Sicily (1759–1816) as Ferdinand III. A Spanish Bourbon, Ferdinand succeeded (1759) to the two kingdoms when his father and predecessor became king of Spain as Charles III. His father's reforms were continued during Ferdinand's minority by the regent, Bernardo Tanucci, but after Ferdinand's marriage (1768) to Marie Caroline a reactionary regime was instituted under her influence. Sir John Acton was appointed prime minister. The execution (1793) of the queen's sister, Marie Antoinette of France, helped turn Ferdinand against France, and in 1798 he joined the Second Coalition. In Jan., 1799, the French took Naples shortly after the royal couple had fled to Sicily. The French-sponsored Parthenopean Republic was short-lived, and terror accompanied Ferdinand's return (June, 1799). Peace was made with France in 1801, but in 1805 Ferdinand joined the Third Coalition against Napoleon. The French reconquered Naples, and early in 1806 the royal couple again fled to Sicily, where Ferdinand ruled under English protection. In 1812 he bowed to local political pressure, made his son regent, and had him grant Sicily a constitution. After Naples was restored to him (1815), Ferdinand abolished Sicilian autonomy and proclaimed (1816) himself king of the Two Sicilies. His reactionary government provoked an insurrection in 1820, and he was forced to grant a constitution. He reestablished his despotism with Austrian aid in 1821 and once again instituted a fierce persecution of all liberals and Carbonari. He was succeeded by his son Francis I.

Ferdinand I or Ferrante (fār-rän´tā), 1423–94, king of Naples (1458–94), illegitimate son and successor (in Naples) of Alfonso V of Aragón. His succession was challenged by Pope Calixtus III, but Pope Pius II made peace with him. Ferdinand promoted commerce, industry, and education, but exercised strict royal control. The great barons, provoked by his ruthless authoritarian policies, called in (1459) John of Anjou, son of René, the rival king of Naples. The barons were defeated (1462) at Troja, and John soon departed. Another conspiracy in 1485 was crushed. Ferdinand's son Alfonso (later Alfonso II) reconquered (1481) the port of Otranto from the Turks. Ferdinand was succeeded by Alfonso II (1494–95), Ferdinand II (1495–96), and Frederick (1496–1501), none of whom was able to defend the kingdom of Naples against France and Spain in the Italian Wars.