• Princess Leonor is the Spanish heir to the throne
  • She turned 18 years old today
  • THIS is what she had to say

It's a big day in the Spanish royal family: Princess Leonor turns 18! The Crown Princess of Spain, also known as the Princess of Asturias, formally swore an oath at the Spanish Parliament today to uphold the constitution, with her parents, King Felipe VI and Queen Letizia, and her sister Infanta Sofía in attendance.

Leonor already looks like a queen

Now, Princess Leonor can legally succeed her father, King Felipe VI, as monarch, and she can act as regent in his absence.

"On turning 18 today, and reaching the age of majority, I have taken the oath provided for in our Constitution. I have sworn 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 fidelity to the King," Princess Leonor said in a statement.

Just like the British royal family, the Spanish monarchy is looking to undergo some changes as the new generation of royals looks ahead. Princess Leonor's birthday, on Tuesday, was marked by a formal ceremony in the Spanish Parliament, at which she swore allegiance to the Constitution before receiving the medals of Congress and the Senate.

Anticipating the event, the Spanish royal family has released a series of photos of the princess, many of them previously unpublished. They include one of her on her first day of school, flanked by her mother, Queen Letizia, and her father, King Felipe VI, who was then still a prince himself.

Her turning of age meant that she had to renew her commitment to the crown and she added:

"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," she said.

Leonor is taking the job seriously

After the event at Parliament, Princess Leonor also received the Collar of the Order of Charles III, the highest civil honor in Spain, in a ceremony at the Royal Palace. Her student career is already very impressive. Princess Leonor, who graduated from UWC Atlantic College of Wales this spring, recently began three years of military training. When she takes the throne one day in the future, she will be the first queen regnant in over 150 years. 

She has already been privy to several state dinners and affairs as the crown looks to introduce her to the public more and more. In an age where European monarchies seems outdated, Leonor will look to bring a youthful energy to the Spanish throne, whenever that will be. For now, she is able to make suggestions and have the king's ear officially.

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Underlining the significance of her birthday, there was also be a reception in the Royal Palace in Madrid, followed by a family gathering in the El Pardo palace, just outside the capital. The release of the photos and a series of recent appearances by the princess leading up to her birthday confirm that, after years of having her image carefully shielded, she is now becoming a very public figure.

"Leonor will need her own narrative," noted royal biographer Carmen Remírez de Ganuza, adding that she "will have to connect with her own digital generation". While the exact nature of that narrative is not yet clear, the build-up to the princess's arrival as a senior royal has gone smoothly.

Let's hope Leonor time in the spotlight will be nothing but positive.