King Charles is watching how Queen Margrethe's decision to strip her grandchildren of their titles plays out, an expert on European royalty says

• It has long been reported that King Charles plans to slim down the British monarchy.
• In Denmark, Queen Margrethe is following a similar path by stripping family members of royal titles.

King Charles III is keeping an eye on how Denmark's queen's decision to strip some of her grandchildren of royal titles plays out as he considers restructuring the British monarchy, a royal expert told Insider.

On Wednesday, Queen Margrethe II announced that four of her eight grandchildren will no longer be able to use the titles of prince and princess from January 2023. Margrethe — now the longest-serving monarch in Europe following Queen Elizabeth II's death — made the announcement in a press release on the official Danish royal website. The statement made clear that her decision came "in line" with how other royal houses are making moves to slim down their monarchies.

It's unclear exactly which royal houses she was referring to, however it's long been reported that Charles has been a proponent of a "slimmed down" British monarchy. As publications including The Telegraph have reported, after inheriting the throne, Charles plans to cut down the number of UK royals from 22 to a core team of seven — including himself, Camilla, the Queen Consort, Prince William, and Kate Middleton.

The Danish royal household and Buckingham Palace did not immediately respond to Insider's request for comment.

Speaking to Insider, Marlene Koenig — an expert in British and European royalty — said that following Margrethe's announcement, it's likely Charles and his team will be taking notes on how his Danish counterpart's decision unfolds.

Margrethe's youngest son Prince Joachim, whose four children — Nikolai, 23; Felix, 10; Henrik, 13; and Athena, 10 — are those impacted by the queen's decision, expressed frustration to Danish outlets about the announcement.

"We are all very sad. It's never fun to see your children being mistreated like that," he told Ekstra Bladet on Thursday. "They themselves find in a situation they do not understand."

Speaking to Danish outlet B.T., Joachim shared how his mother's decision "upset" his children. "Why should their identity be removed?" he said. "Why must they be punished in that way?"

Charles is taking notice, according to royal expert Marlene Koenig

"Charles and his advisors are watching what has happened," Koenig said. "And one would hope that if he does a surgical strike and removes royal titles from, say the York princesses, he talks with them first."

Koenig referenced Princess Eugenie and Princess Beatrice — Charles' nieces through his brother Prince Andrew — but other royals who may be at risk of losing titles also include Prince Harry and Meghan Markle's children, Archie and Lilibet, who were technically entitled to start using royal titles after Queen Elizabeth II's death. As Insider's Samantha Grindell reported, citing Today, King George V's 1917 Letters Patent states that the monarch's children and grandchildren are able to use the titles as their direct descendants. (As of Friday, it remains unclear whether Harry and Meghan's children will use these titles; the British royal family's website lists Archie and Lilibet as "master" and "miss," respectively.)

But while Charles and his advisors may be keeping tabs on reactions to Margrethe's decision to strip her grandchildren of royal titles, Koenig also said the focus will remain on what is best for the future of the monarchy in the UK.

"Charles would be aware of the changes in other houses but the focus is solely on what to do in the UK," she added. "What happens in other monarchies is not relevant to the British."

Although Charles is a distant relative of Margrethe through their shared ancestry via Queen Victoria, the relationship between British monarchs and those in Europe has grown distant over time, Koenig said.

In Scandinavia, she said, royal houses maintain close relationships. "The Scandinavian monarchies are close friends and get together even for private vacations," she said. "The three heirs keep in touch."

"The British royals do not mix and mingle often with the other European royals," Koenig added.

But camaraderie still exists to an extent between the UK and European royals. Margrethe and Queen Elizabeth II, for example, kept a long-lasting friendship. The Danish queen was the first international royal to send a letter of condolence to King Charles III, The Independent reported.

"I send you and Camilla my warmest thoughts and prayers," Margrethe said, according to the publication. "She was a towering figure among the European monarchs and a great inspiration to us all. We shall miss her terribly."