By Marisa Laudadio
8:11pm PDT, Nov 2, 2023
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Halloween was a very big — and historic — day for Princess Leonor of Spain.
Not only was it her 18th birthday, but it was the day the future queen pledged her loyalty to her country's constitution before the lower house of Spanish parliament, which means she can now act as regent in the absence of her father, King Felipe VI, and will ascend the throne immediately upon his death.
Leonor will one day become Spain's first queen regnant since Queen Isabella II, who reigned from 1833 to 1868.
The Princess of Asturias's big day was marked by her family's pride — as well as some major controversy.
Divisions over the monarchy were highlighted by boycotts by leftist and separatist politicians who refused to attend the major event. Reuters reported that the acting ministers of equality, social rights and consumer affairs all declined to attend because they believe hereditary and unelected head of state is undemocratic, Reuters reported, adding that lawmakers from movements supporting the independence of Catalonia, the Basque Country and Galicia likewise did not attend.
Join us as we take a look at the best photos from Leonor's 18th birthday…
Crown Princess Leonor smiled as she swore her allegiance to her country's constitution before the Cortes Generales in the Congress of Deputies, the lower house of Spain's congress, in Madrid on Oct. 31, 2023 — her 18th birthday.
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Spain's Crown Princess Leonor posed with her family — King Felipe VI, Queen Letizia and Princess Sofia — after being presented with the Collar of the Royal and Distinguished Spanish Order of Carlos III, which is the highest order of chivalry in Spain, at the Royal Palace following a ceremony in which she swore allegiance to Spain's constitution at the Spanish Lower House in Madrid, Spain, on Oct. 31, 2023 — her 18th birthday.
Upon her father's death, Leonor will become Spain's first queen regnant since Queen Isabella II, who reigned from 1833 to 1868.
MORE: The best photos of future queen Princess Leonor as she begins her army training in Spain
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Crown Princess Leonor of Spain and her younger sister, Princess Sofia, smiled during a reception after the future queen was presented with the Collar of the Royal and Distinguished Spanish Order of Carlos III, which is the highest order of chivalry in Spain, at the Royal Palace in Madrid following a ceremony in which she swore allegiance to Spain's constitution on Oct. 31, 2023 — her 18th birthday.
MORE: The cutest photos of the Prince and Princess of Wales' children
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Crown Princess Leonor of Spain watched a military parade after a ceremony in which she swore allegiance to Spain's constitution at Spanish parliament in Madrid on her 18th birthday — Oct. 31, 2023.
When she takes the throne upon her father's death, Leonor will serve as supreme commander of the Spanish armed forces.
In anticipation of that day, in the summer of 2023, she began what will total three years of military training. She is currently training with the army and will next study with other branches to prepare her for her future duties.
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Spain's Crown Princess Leonor and her family — sister Princess Sofia and their parents, Queen Letizia and King Felipe VI — arrived at the Lower House of Spain's parliament in Madrid before a ceremony in which she swore allegiance to Spain's constitution on Oct. 31, 2023 — her 18th birthday.
Her father made the same pledge on his 18th birthday in 1986.
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Spain's Crown Princess Leonor delivered a speech after receiving the Collar of the Royal and Distinguished Spanish Order of Carlos III, which is the highest order of chivalry in Spain, at the Royal Palace in Madrid following a ceremony in which she swore allegiance to Spain's constitution on Oct. 31, 2023 — her 18th birthday.
"From today I owe myself to all Spaniards, whom I will serve at all times with respect and loyalty. There is no greater pride. On this very important day — which I will always remember with emotion — I ask you to trust me, as I have put all my trust in our future, in the future of Spain," Leonor, the Princess of Asturias, said in her speech. "I have solemnly, formally and publicly committed myself to our democratic principles and our constitutional values, which I fully assume. And I have assumed a great responsibility towards Spain before the Cortes Generales, which I hope to reciprocate with the greatest dignity and with the best example."
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Crown Princess Leonor swore allegiance to her country's constitution at Spain's parliament in Madrid on Oct. 31, 2023 — her 18th birthday.
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On Oct. 31, 2023 — her 18th birthday — Spain's Crown Princess Leonor swore an oath to her country's constitution before Cortes Generales President Francina Armengol as parents King Felipe VI and Queen Letizia and sister Princess Sofia looked on inside the Congress of Deputies in Madrid.
After taking the oath, Leonor can now legally serve as her father's regent if necessary and automatically becomes head of state in the event of his death.
"I swear to faithfully carry out my duties, to keep and ensure that the Constitution and the laws are kept, to respect the rights of citizens and the Autonomous Communities, as well as loyalty to the king," Leonor said during the ceremony, according to the Spanish royal court.
Armengol accepted her oath and replied, "The Cortes Generales have just received the oath that Your Highness has taken, in compliance with the Constitution, as heir to the Crown. Ladies and gentlemen. Long live the Constitution! Long live the king! Long live Spain!"
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This is a general view inside the ceremony in which Spain's Crown Princess Leonor — on the left in a white suit — swore allegiance to the Spanish constitution before Spain's parliament in Madrid on her 18th birthday, Oct. 31, 2023.
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Spain's Crown Princess Leonor, King Felipe VI, Queen Letizia and Princess Sofia stood alongside Prime Minister Pedro Sanchez at the Congress of Deputies in Madrid where the future queen swore allegiance to Spain's constitution on Oct. 31, 2023 — her 18th birthday.
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Crown Princess Leonor of Spain watched a military parade after a ceremony in which she swore allegiance to Spain's constitution at Spanish parliament in Madrid on her 18th birthday — Oct. 31, 2023.
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Spain's Crown Princess Leonor, King Felipe VI, Queen Letizia and Princess Sofia stood alongside Prime Minister Pedro Sanchez outside the Lower House in Madrid where the future queen swore allegiance to Spain's constitution on Oct. 31, 2023 — her 18th birthday.
