Under the law, the monarchy was to be understood as “established” according to the principles of the national alzamiento of 1936 and detached from any other consideration of legitimacy: therefore Juan Carlos, nephew of the last king Alfonso XIII and educated in Spain where he served in the army, was preferred to his father, Juan Count of Barcelona, and to the Carlist candidates of the branch of the Bourbons-Parma. In July 1972 Carrero Blanco was appointed Franco’s successor in the government, taking over the presidency in July of the following year. Expert in an attack in December 1973, Carrero Blanco was replaced in February 1974 by C. Arias Navarro, with whom Spain had, for the first time since 1939, a civilian at the head of the government. After the exoneration of General Díez Alegría from the post of chief of staff in June of the same year, in July-August Juan Carlos, due to an infirmity of the now octogenarian Franco, he assumed the substitute post of head of state for 46 days. The law on associations passed in January 1975 – under which all associations that had at least 25,000 members could carry out political activity under the supervision of the Movimiento – gave the possibility to form embryos of political parties.
During Franco’s last illness the prince-designate was again interim head of state and, after the death of the dictator, on November 20, 1975, he became king under the name of Juan Carlos I. Arias Navarro remained in the presidency after a reshuffle of the government in December: cautious reform intentions resulted among other things in the announcement of the forthcoming institution of a bicameral Parliament. The president of the government, too compromised with Francoism, was replaced on 3 July 1976 by A. Suárez González, who, despite being the general secretary of the Movimiento, he was able to skillfully guide the liquidation of the old structure of the regime. In July, parties were legalized with the exception of those on the extreme left or in favor of separatism, and gradually the 650 political prisoners were released; the establishment of a Congreso of 350 freely elected deputies, and of a Senado composed of 207 elected senators as well as some designated by the sovereign, was approved by the Cortes in November and also by popular referendum the following month. The democratization process then continued, not without temporary stagnation, until it resulted in the granting of total freedom of political and trade union organization, the return of the exiles, etc. The elections by universal suffrage held on 15 June 1977 saw – not without some irregularities – the success of the premier ‘s Unión de Centro Democrático (UCD)Suárez, who obtained 166 out of 350 deputies in the Chamber; and the Partido Socialista Obrero Español (PSOE) with 118 deputies; the other parties are far behind, from the communists (19 seats) to the center-right grouping Alianza Popular (16 seats), to the Catalan and Basque regional parties. Suárez formed a new government in July which has shown that it can count on the votes of the UCD and on occasion those of the regional parties. The problem of the economic recession – with an inflation rate of almost 30% in 1977, a fall in investment and productivity, strikes and rising unemployment – led the government to enter into a program agreement in October with all the formations represented in Parliament. Alongside the economic problems, pre-eminent is that of regional autonomies:Catalan existing before the civil war was reconstituted in September, and a coalition government was formed pending the handover of power from Madrid to Barcelona; in the Basque Country some parts of the ETA have not given up the armed struggle.
In February 1978, a government reshuffle brought elements close to the Spanish Confederation of Business Organizations to the economic ministries; at the same time government policy was oriented towards a social market economy (Suárez speech at the Cortes, April 5, 1978). In the Spanish and more generally European context, the position of the Communist Party has assumed particular interest, characterized by decisive declarations of pluralism and Europeanism, in controversy with Soviet ideology (publication of the essay Eurocomunismo y Estado of Spain Carrillo in 1977, rejection of Leninism and “democratic centralism” in April 1978). In the referendum for the new constitution (6 December 1978), votes in favor (88%) prevailed over those against (8%); but the abstentions reached a very high level (33% of the electorate), especially in the Basque provinces where barely a third of those registered on the lists declared themselves for the constitutional law. However, this sanctioned the role of parties and trade unions, the regional order and the full separation between State and Church, in a monarchical institutional framework. In full crisis of public order (in January 1979 the leaders of the military and judicial power were hit by terrorism), new elections were called for by all parties (except the Communist Party, instead in favor of a government of national unity), as a necessary popular sanction of the new political system. The consultation of 10 March 1979 was characterized by a substantial stability of the electorate, but also by a high rate of abstention (30%): UCD and PSOE maintained their respective positions, while the Communist Party made slight progress and the moderate right declined; The success of the Basque separatists and the nationalists of Andalusia and the Canary Islands has assumed worrying dimensions. On 6 April Suárez formed the new government.
The international orientation of the Spain has also been gradually updated. The renewal of military bases on Spanish territory was granted despite the accident of January 1966, when four defused hydrogen bombs crashed in Palomares following a collision between two American planes. The permanent conflict with Great Britain for Gibraltar sharpened from 1964 due to the British decisions to expand the autonomy of the territory, to which the Spain responded by blocking the land border and boycotting the enclave. in order to regain sovereignty. The process of decolonization of the Spanish territories in Africa saw the granting of independence to Equatorial Guinea on 12 October 1968, the cession of Ifni to Morocco on 10 July 1969 and the evacuation from the Spanish Sahara on 26 February 1976; the subject of Moroccan claims are also Ceuta, Melilla and some small islands on the North African coast, while the independence of the Canary Islands is supported by Algeria and Libya. The Iberian Pact, which linked Spain to Portugal since the end of the civil war, ceased in October 1977. The themes of foreign policy remained those of Europe (since October 1971 a preferential agreement has been in force with the EEC), the Atlantic alliance and relations with African states; but contacts with Iran, the Arab world and China have also been developed. In January 1978, receiving the diplomatic corps accredited in Madrid, Juan Carlos expressed his desire to open international relations in every direction, placing his policy within the general framework of détente, European security and the development of human rights, but also expressing some reservations about recent African tensions. As for joining NATO, Communists and Socialists have declared their opposition, while the government is attempting a progressive approach.