Juan Carlos I (born 1938), proclaimed king of Spain on November 22, 1975, played an instrumental role in the transformation of his nation from a dictatorship to a constitutional monarchy.

Juan Carlos Víctor María de Borbón y Borbón was born in the Anglo-American Hospital in Rome, Italy, on January 5, 1938. His grandfather, Alfonso XIII, had been king of Spain from 1902 to 1931, after which Spain became a republic. With the emergence of Francisco Franco's fascist dictatorship in 1939, the father of Juan Carlos, Don Juan de Borbón y Brattenberg, became a pretender to the Spanish throne and a hostile critic of Franco's regime, which endured until 1975.

Juan Carlos' early years were spent in exile in Rome, Lausanne, Switzerland, and Estoril, Portugal. He did not set foot on Spanish soil until Franco summoned him to "supervise" his education. After completing his high school education in...