The kings and princes of Spain who swore an oath to the Constitution before Leonora.

On her 18th birthday, October 31, Princess Leonor de Bourbon of Asturias must appear before the Senate to swear allegiance to the Constitution before the Cortes, as provided for in Article 61 of the Constitution itself. This ceremony is an integral part of the process of legitimizing the heir to the throne as the future head of state and symbolizes the future monarch's submission to the law, which is consistent with a parliamentary monarchy.

Since the adoption of the first Spanish constitution in 1812, this ceremony has only one predecessor, its father, the current King Felipe VI, but in the 19th and 20th centuries there have been various similar ceremonies with different kings or regents swearing allegiance to the constitution as a necessary''requirements for their proclamation by a sovereign people.

Fernando VII

Fernando VII was the first Spanish monarch to be forced to swear allegiance to the constitution issued by the Cortes of Cadiz in 1812, during the War of Independence against French occupation. His life and reign were agitated and they marked the end of absolutism in Spain. Already heir, he organized various plots against his father to remove him from the throne and then went into exile with him to give way to José Bonaparte, brother of the Emperor of the French, Napoleon I.

After returning from exile, he organized a coup d'état against the liberal regime established during the War of Independence and in''for six years ruled as an absolute monarch, which was his wish. In 1820 the rebellion of General Riego, of a liberal character, compelled the king to restore the previous constitutional regime and to swear, though reluctantly, allegiance to the Constitution of 1812.

From Isabella II to Amadeo I

When Fernando VII died on the throne in 1833, he was succeeded by his daughter Isabella, who was only three years old. Ten years later, on November 10, 1843, Isabella II swore another Spanish constitution, 1837, at the same ceremony in which the Cortes had preceded her to adulthood, so that she could rule without the tutelage of the regents (her mother Maria Cristina and General Espartero) who ruled on her behalf.

But the agitated nineteenth century devoured this monarchy as well, which''overthrew the Revolution of 1868, the "Glorious" Revolution. Then came a tumultuous period of six years, beginning with the proclamation of a new constitution that retained constitutional monarchy as the form of government but excluded the Bourbons from the leadership of the state.

The search for a successor to the throne ended the following year with the Cortes' choice the following year of Amadeo di Savoia, the youngest son of King Victor Emmanuel II, a unifier of Italy with modern and liberal views. Immediately after his arrival in Madrid on January 2, 1871, Amadeo I visited the memorial chapel of his great protector, General Prim, who had been killed in an assassination attempt three days before, and then proceeded to the Cortes to swear in the new constitution that had arisen in 1869: "I accept the Constitution and swear to observe and''to defend the Laws of the Realm,' was the chosen formula, after which he was proclaimed king.

Alfonso XII

The reign of Amadeo I lasted only two years and was marked by fierce opposition from the Carlists, the Bourbons, the Republicans and part of the aristocracy, who reproached him for being a foreigner.

Alfonso XII received news of his proclamation of exile in Paris, and on his arrival in Madrid on January 14, 1875, he did not''s majority on May 17, 1902, the day of his 16th birthday. On that day the new monarch, dressed in the uniform of a captain-general, took an oath before the Cortes and many members of the Spanish nobility and the royal houses of Europe in the following words: "I swear before God, on the holy Gospels, to uphold the Constitution and the laws. If I do so, may God succeed me, and if I do not, may He demand it of me. "

With Felipe VI and the principles of the Movement

With the proclamation of the Second Spanish Republic on March 14, 1931, and Alfonso XIII's hasty flight into exile, a long period of more than 40 years without a monarch began, including nearly four decades of Francisco Franco's dictatorship. The dictator decided to appoint an heir at the head of state, Alfonso XIII's grandson Juan Carlos I, who on July 23, 1969 vowed''fidelity to the Principles of the Movement, the Fundamental Laws of the Franco regime.

In front of the procurators (as deputies were called to distinguish themselves from parliamentary tradition), the then Prince of Spain swore 'allegiance to His Excellency the Head of State and fidelity to the Principles of the National Movement and other Fundamental Laws of the Kingdom'.

Juan Carlos I repeated the same oath on November 22, 1975, following his proclamation as King of Spain by the then-Franco Cortes, two days after the dictator's death. Eleven years later, after a political reform that abolished the Fundamental Principles and adopted a new constitution that consolidated the parliamentary monarchy, on January 30, 1986, on his 18th birthday, dressed in civilian clothes, Felipe de Bourbon''swore allegiance to the 1978 Constitution and to his father in the Congress of Deputies building with the following words: 'I swear to faithfully fulfill my duties, to respect and defend the Constitution and laws, to respect the rights of citizens and autonomous communities, and to be loyal to the King'.

Felipe VI swore allegiance to the Constitution as prince and as king 28 years apart and with an almost identical formula.

On June19, 2014, the Cortes proclaimed Felipe VI as king, this time wearing a military uniform, after he repeated literally the formula used 28 years earlier (except for the part about allegiance to the king) "in accordance with Article 61 of the Constitution," as the then president of the Lower House Chamber, Jesús Posada, reminded him. That formula, according to historians of the 1980s, was