For the first time in 900 years, kings and queens from around the world are going to a British coronation. Take a look at all the royals attending King Charles' big day.

It may be early days into his reign, but King Charles has already shown he's not afraid of breaking royal traditions.

According to The Times of London, Charles' coronation will be the first in 900 years of British history, including that of his mother Queen Elizabeth II, to welcome international monarchs. The tradition of not inviting them had been followed previously in coronations because the ceremony represents a sacred connection between the monarch, their people, and God. 

But since Charles is doing away with the tradition, take a look at all of the royals who have confirmed their attendance at his coronation, set to take place at Westminster Abbey on May 6. 

Prince Albert was one of the first international royals to confirm his and Princess Charlene's attendance at Charles' coronation.

Speaking to People in January, Albert said he was "certain that it's going to be an incredible ceremony and a very moving one.

"I'm certain His Majesty will add his own 'personal touches' to the ceremonies, but what those will be, I'm sure I don't know," he added.

At the time, Albert also said he and Charlene were undecided on whether they'd be bringing their 8-year-old twins, Prince Jacques and Princess Gabriella, in tow, saying they "may be a little young for these types of ceremonies."

According to the BBC, King Carl Gustaf will be joined by his daughter, Crown Princess Victoria, at Charles' coronation. 

Like many other European royals, Carl – who has reigned as King of Sweden since 1973 – is a distant relative of Charles through their shared ancestor, Queen Victoria. Carl is the third cousin of the late Queen Elizabeth II, according to Royal Central.

Victoria became his heir in 1980 when he changed Sweden's laws of succession to allow her to inherit the throne, Insider previously reported.  

On Monday, the Royal House of the Netherlands released a statement confirming King Willem-Alexander and Queen Máxima will attend the coronation ceremony of Charles and Queen Camilla at Westminster Abbey.

It added that their daughters, Princess Beatrix and Catharina-Amalia, the Princess of Orange, will attend a Buckingham Palace reception the evening before the coronation. 

As Insider previously reported, 19-year-old Catharina-Amalia is heir to the Dutch throne and is currently studying politics, psychology, law, and economics at the University of Amsterdam.

As Queen Margrethe II recovers from a back surgery that took place in February, the Danish royal family will be represented at Charles' coronation by Crown Prince Frederik and Crown Princess Mary.

Their attendance was confirmed in a statement issued by the Danish Royal House. 

Frederik, the heir to the throne, accompanied his mother Margrethe to Queen Elizabeth II's funeral in September 2022. After the death of her British counterpart and distant relative, Margarethe inherited the unofficial title of Europe's longest-living reigning monarch. The pair were not only relatives – through Queen Victoria – but friends.

According to The Independent, the Danish queen was the first international royal to send a letter of condolence to Charles.

Also representing their country at the coronation are Crown Prince Haakon and Crown Princess Mette-Marit of Norway, according to the upcoming program on the royal house's website. 

The couple, who tied the knot in 2001 and have two children, are attending in place of King Harald V and Queen Sonja. 

Haakon, who is heir to the throne, and Mette-Marit visited the UK recently. They were welcomed at Windsor Castle by Prince William and Kate Middleton during their two-day visit in March.

According to a tweet from Kensington Palace at the time, the two couples spent their time together "discussing green energy, the environment and much more."

In April, Crown Prince Akishino and his wife, Princess Kiko, were approved to go on a four-day trip to the UK to attend Charles' coronation, the Japan Times reported. 

According to the outlet, the Imperial Household Agency noted that the occasion marks the first time either Akishino or Kiko have visited the UK or been to a foreign royal coronation.

Akishino is being sent to represent his brother, Emperor Naruhito, who cannot attend due to customs that restrict him from being present at the coronation of international monarchs. 

As Tatler reports, Luxembourg's Henri and Maria Teresa will be representing their nation at Charles' coronation. 

The Grand Duke — whose title is equivalent to king — was heir to the throne when the couple was first introduced by their parents in the late 1970s, Insider's Mikhaila Friel previously reported.

Luxembourg is one of 12 monarchies still active in Europe today, World Population Review reports. That said, Maria Teresa, whose title is equivalent to that of a queen consort, told Insider the country is the only Grand Duchy — a country headed by a grand duke or duchess.

According to Town & Country, Queen Anne Marie, Crown Prince Pavlos, and his wife, Crown Princess Marie-Chantal, are among those confirmed to attend Charles' coronation. 

Pavlos is among Charles' 33 godchildren and had a close relationship with the king's late father, Prince Philip.

According to Hola, when Philip died in April 2021, Pavlos shared a tribute saying that the 99-year-old, who was born on the Greek island of Corfu, had "been a very loved member of the extended Greek family and of course a strong connection for us to Britain where my brother Philippos was born and given his name by my parents."

Representatives for Queen Anne Marie and Crown Prince Pavlos did not immediately respond to Insider's request for comment. 

Another distant relative of Charles with royal roots is Margareta of Romania, who Tatler reports has confirmed her attendance for the coronation. The pair are second cousins once removed through Queen Victoria, and third cousins through King Christian IX of Denmark, who ruled until 1906, according to the Express. 

Margareta's official title is Custodian of the Romanian Crown. She inherited the title from her father King Michael, who died in 2017, according to Royal Central. He was the last monarch of the country to rule before the institution was made defunct in 1947, The Economist reports.

According to Hola, the Spanish news agency EFE received confirmation from the Casa Real – the Spanish monarchy – that King Felipe VI and Queen Letizia of Spain will be attending Charles' coronation. 

Much like other European royal dynasties, Felipe also has British royal roots on his paternal side. His paternal great-grandfather, King Alfonso XIII, married Queen Victoria's granddaughter Princess Victoria Eugenie (who later became Queen of Spain), Insider previously reported. 

Felipe and Letizia also appear to have a close relationship with their British counterparts. As Insider previously reported, they sent a personal letter to the Queen after Prince Philip died in 2021. In the letter, they referred to the Queen as "Aunt Lilibet" and Philip as "our dear Uncle Philip," in a nod to their shared roots. 

Representatives for King Felipe VI and Queen Letizia did not immediately respond to Insider's request for comment.