Juan Carlos (Juan Carlos Alfonso Víctor María de Borbón y Borbón-Dos Sicilias) reigned as King of Spain from 1975 to 2014, when he abdicated in favour of his son, Felipe VI.
Generalísimo Francisco Franco, the Spanish dictator, took over the government of Spain from the short-lived Second Spanish Republic by leading a successful rebellion in 1939, and ruled as "Regent to the [exiled] King of Spain". In 1969, he chose Prince Juan Carlos, grandson of King Alfonso XIII, to be the next head of state, bypassing his father Juan de Borbón and expecting him to continue Franco's own authoritarian regime. Juan Carlos became King on 22 November 1975, two days after Franco's death, the first reigning monarch since 1931. His father did not abdicate in favor of his son until 1977. Soon after enthronement, however, Juan Carlos introduced reforms to dismantle the Francoist regime and begin the Spanish transition to democracy. This led to the approval of the Spanish Constitution of 1978 in a referendum, which established a constitutional monarchy. In 1981, Juan Carlos played a major role in preventing a coup that attempted to revert Spain to Francoist government in the King's name.
During his reign, Juan Carlos served as the president of the Ibero-American States Organization, representing over 700 million people in its 24-member nations of Spain, Portugal, and their former American colonies. In 2008, he was considered the most popular leader in all Ibero-America.
In 1962, Juan Carlos married Princess Sofía of Greece and Denmark, with whom he has three children. Juan Carlos and Sofía retain the titles and style they enjoyed during his reign.