Two days after the death of Francisco Franco, Juan Carlos I was declared King of Spain according to the law of succession promulgated by Franco.

Francisco Franco Bahamonde was a Spanish general and dictator who led the Nationalist forces in overthrowing the Second Spanish Republic during the Spanish Civil War and thereafter ruled over Spain from 1939 to 1975, assuming the title Caudillo. This period in Spanish history, from the Nationalist victory to Franco's death, is commonly known as Francoist Spain or as the Francoist dictatorship.

Juan Carlos I is a member of the Spanish royal family who reigned as King of Spain from 22 November 1975 until his abdication on 19 June 2014. In Spain, since his abdication, Juan Carlos has usually been referred to as the rey emérito by the press.

The monarchy of Spain or Spanish monarchy is the constitutional form of government of Spain. It consists of a hereditary monarch who reigns as the head of state, being the highest office of the country.

An order, line or right of succession is the line of individuals necessitated to hold a high office when it becomes vacated, such as head of state or an honour such as a title of nobility. This sequence may be regulated through descent or by statute.