Juan Carlos I, the last King of Spain reigned from 1975 until his abdication in 2014. Juan Carlos Alfonso Víctor María de Borbón y Borbón-Dos Sicilias was born on January 5, 1938 in Rome, Lazio, Italy, during his family's exile. Expected to continue Franco's legacy, Juan Carlos, however, soon after his accession 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 re-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. In 2008, he was considered the most popular leader in all Ibero-America.

Juan Carlos I de España (Roma, 5 de enero de 1938) ha sido el rey de España desde el 22 de noviembre de 1975 hasta el 18 de junio de 2014, cuando abdicó la Corona en su hijo Felipe VI. Tras su renuncia, continúa ostentando el título de rey con carácter honorífico y mantiene el tratamiento de «majestad», además de ser capitán general de las Fuerzas Armadas en la reserva.8​9​10​ No ejerce ningún tipo de función constitucional.