Spain's King Felipe VI and Queen Letizia will celebrate their 20th wedding anniversary on Wednesday, widely credited with having regenerated the scandal-tainted monarchy for a new era.

To mark the occasion the royals released over the weekend a series of previously unseen pictures of them posing along with their daughters, Princess Leonor, 18, and Princess Sofia, 17, in the gardens of Madrid's royal palace. No public events are planned.

Felipe, then 36, exchanged vows and gold rings with Letizia Ortiz, a 31-year-old divorced journalist, at Madrid's Almudena Cathedral on a rainy May 22, 2004 in a lavish ceremony attended by statesmen and royalty from around the world.

He became king -- and Letizia Spain's first commoner queen -- after his father, Juan Carlos, abdicated in June 2014 following a series of scandals over his finances and love life which caused the popularity of the royal family to plunge.

Adding to the monarchy's woes, Felipe's elder sister, Princess Cristina, was indicted on tax fraud charges. She was later acquitted.

"The crown was in crisis, and they turned things around during these 10 years," Javier Ayuso, who headed the royal palace's communications departments between 2012 and 2014, told AFP.

Pilar Eyre, the author of a series of books about the monarchy, said Felipe and Letizia "found the crown in a deplorable state".

"Everyone was saying that they were not going to last and that the monarchy's days were numbered," she told AFP.

-'Code of conduct' -

The new king promptly ordered an audit of the royal household's accounts and issued a "code of conduct" for its members.

Then in 2020 Felipe renounced any future personal inheritance he might receive from his father and stripped him of his annual allowance after fresh details of his allegedly shady dealings emerged.

Even though investigations of Juan Carlos's finances in Spain and Switzerland have since been dropped, Felipe has continued to keep a distance from his father, who left Spain for Abu Dhabi in 2020.

The royal couple have also loosened protocol at most events to try to "bring the crown closer to the citizens," said Ayuso.

The daughter of a nurse and the granddaughter of a taxi-driver, Letizia initially faced opposition from Spain's most conservative factions when she married Felipe.

"It was a milestone in Spain's contemporary history because no crown prince had ever married a person deemed unequal, that is not being royal," Jose Antonio Zarzalejos, a royal expert and former director of the conservative daily newspaper ABC, told AFP.

- 'Breath of fresh air' -

Felipe and Letizia dated in secret before their engagement was announced in November 2003.

But to her supporters, Letizia's down-to-earth middle-class roots are an asset.

"She has brought one of the ingredients needed to maintain a monarchy: closeness to the people," said Ayuso, adding that the queen has brought "a breath of fresh air to the crown".

Since the royal couple's eldest daughter Leonor turned 18 on October 31 last year, the public has increasingly turned its attention to the heir to the Spanish throne.

Leonor swore loyalty to the Spanish constitution that day during a nationally televised ceremony in the lower house of parliament, a necessary step for her to be able to succeed to the crown and someday become queen.

She has appeared frequently in the media lately along with the term "Leonormania," underlining her growing popularity as the modern face of the future monarchy.

"The future of the Spanish monarchy now depends more on Leonor than on Letizia," journalist Abel Hernandez, the author of several books on the royal family, told AFP.