Juan Carlos I is a former king of Spain, who reigned from 1975 until his abdication in 2014. He played a crucial role in the transition of Spain from a dictatorship under Francisco Franco to a constitutional monarchy, helping to establish democracy in the country. Born on January 5, 1938, in Rome, Italy, Juan Carlos was educated in Spain and abroad. His reign saw significant political and social changes, including the approval of the Spanish Constitution in 1978. After stepping down, he was succeeded by his son, Felipe VI.