He also expresses the State's assent to entering into international commitments through treaties; and he declares war or makes peace, following the authorization of the Cortes Generales.

In practical terms, his duties are mostly ceremonial, and constitutional provisions are worded in such a way as to make clear the strict neutral and apolitical nature of his role.

By an overall majority, the Senate is the institution that authorizes the Government to adopt measures to enforce an autonomous community's compliance with its constitutional duties when it has failed to do so.

The oath of office used is: "I swear/promise to faithfully carry out the duties of the position of president of the Government with loyalty to the King; to obey and enforce the Constitution as the fundamental law of the State, as well as to keep in secret the deliberations of the Council of Ministers".

[20] Though the body has existed intermittently since medieval times, its current composition and the nature of its work are defined in the constitution and subsequent laws that have been published, the most recent in 2004.

It is currently composed of a president, nominated by the Council of Ministers, several ex officio councillors – former prime ministers of Spain, directors or presidents of the Royal Spanish Academy, the Royal Academy of Jurisprudence and Legislation, the Royal Academy of History, the Social and Economic Council, the Attorney General of the State, the Chief of Staff, the Governor of the Bank of Spain, the Director of the Juridical Service of the State, and the presidents of the General Commission of Codification and Law – several permanent councilors, appointed by decree, and no more than ten elected councilors in addition to the council's Secretary General.

The Council of State serves only as an advisory body, that can give non-binding opinions upon request and to propose an alternative solution to the problem presented.

They are to be renowned magistrates and prosecutors, university professors, public officials or lawyers, all of them jurists with recognized competence or standing and more than 15 years of professional experience.

Outlawed during Franco's dictatorship, it gained recognition during the Spanish transition to democracy period, when it officially renounced Marxism, under the leadership of Felipe González.

It governed Spain under the prime ministership of José María Aznar from 1996 to 2004, and again from December 2011, and after much uncertainty caused by the inconclusive results of the 2015 general election and the 2016 election when the People's Party formed a minority government with confidence and supply support from liberal Ciudadanos (Cs) and the Canarian Coalition (CC), which passed due to the Spanish Socialist Workers' Party (PSOE) abstaining.

The motion was successful and resulted in the PSOE leader Pedro Sánchez becoming the new Prime Minister of Spain until his 2019 state budget was rejected requiring him to call a snap election for 28 April of the same year.

Even though Juan Carlos I had sworn allegiance to "National Movement", the sole legal party of the regime, he expressed his support for a transformation of the Spanish political system as soon as he took office.

Such an endeavor was not meant to be easy or simple, as the opposition to the regime had to ensure that nobody in their ranks would turn into extremism, and the Army had to resist the temptation to intervene to restore the "Movement".

In 1976 he designated Adolfo Suárez as prime minister – "president of the Government" – with the task of convincing the regime to dismantle itself and to call for elections to a Constituent Assembly.

Spain's transformation from an authoritarian regime to a successful modern democracy was a remarkable achievement, even creating a model emulated by other countries undergoing similar transitions.

In October 1982, the Spanish Socialist Workers' Party, led by Felipe González, swept both the Congress of Deputies and Senate, winning an absolute majority in both chambers of the Cortes Generales.

The government also created new social laws and large scale infrastructural buildings, expanding the educational system and establishing a welfare state.

In the aftermath of the terrorist bomb attacks in Madrid, which occurred just three days before the elections, the Spanish Socialist Workers' Party won a surprising victory.

[45] In March 2011, Rodríguez Zapatero made his decision not to lead the Socialist Party in the coming elections, which he called ahead of schedule for 20 November 2011.

The People's Party, which presented Mariano Rajoy for the third time as candidate, won a decisive victory,[45] obtaining an absolute majority in the Congress of Deputies.

[48] In June 2018, Pedro Sánchez, leader of Spanish Socialist Workers' Party (PSOE), was sworn in as the country's new prime minister after conservative Mariano Rajoy was defeated in a no-confidence vote in parliament.

[51] Spanish political developments since the early twentieth century have been marked by the existence of peripheral nationalisms and the debate of whether Spain can be viewed as a plurinational federation.

Spain is a diverse country with different and contrasting polities showing varying economic and social structures, as well as different languages and historical, political and cultural traditions.

[58] Thus tensions between peripheral nationalism and centralism continue, with some nationalist parties still advocating for a recognition of the other 'nations' of the Spanish Kingdom or for a peaceful process towards self-determination.

This law sought to determine the language of instruction and curriculum content and was seen as encroaching upon already devolved powers[60] and at odds with existing statutes of autonomy.

However one aspect of this asymmetry is a cause of friction (eg in Catalonia), namely that the Basque Country and Navarra can raise their own taxes and negotiate a transfer to Madrid to pay for common services and hence, unlike the other regions, do not contribute to fiscal equalisation across Spain.

PSOE, CiU, ERC, PNV, IU-ICV, CC and the mixed group —BNG, CHA, EA and NB— supported it with a total of 192 votes, while the 147 PP parliamentarians objected.

In the years leading up to the permanent cease-fire, the government had had more success in controlling ETA, due in part to increased security cooperation with French authorities.

In a June 2000 communiqué following the explosions of two small devices in Barcelona, GRAPO claimed responsibility for several attacks throughout Spain during the past year.

Even on many international issues beyond Western Europe, Spain prefers to coordinate its efforts with its EU partners through the European political cooperation mechanisms.