Franco's chosen heir turned out to be a key to Spanish democracy
Francisco Franco named Prince Juan Carlos his successor in 1969, and for six years the prince seemed content to follow the dictator's path. Yet after Franco died in November 1975, the new king helped steer Spain to a democratic constitution, approved by referendum in December 1978.
Juan Carlos, grandson of Alfonso XIII, began strictly within Franco's legal framework: he swore loyalty to the principles of the National Movement, took the crown before the Francoist Cortes and followed existing law when choosing his first head of government. Only in his speech to the Cortes did he hint at change. His father, Don Juan de Borbón, had backed constitutional monarchy since 1946 and did not give up his own claim until 14 May 1977.
The balance was delicate. Far-right Francoists had strong support in the army, while the left distrusted a king who owed his throne to Franco. As commander-in-chief, the king's backing was vital in keeping the army loyal and letting the government retire generals who saw it as their duty to defend the old order. Western governments led by the United States favoured a constitutional monarchy.
At first the holdover prime minister, Carlos Arias Navarro, spoke of a democracy in the Spanish way that would preserve Francoism, and adopted Manuel Fraga's plan for gradual, controlled reform. Pressure from society and politics pushed further: the 1977 general election produced a democratic parliament with the mandate to draft a new constitution, and most key decisions were reached by consensus between government and opposition.
The process is often held up as a model of peaceful negotiation, but political violence was far more common than in the comparable transitions of Greece and Portugal, with separatist, leftist, fascist and vigilante groups and police abuses, plus an attempted coup. The Transition is usually said to end with the Socialist landslide of 1982, the first peaceful handover of executive power, and it opened the way to Spain joining Europe.
Source: Spanish transition to democracy