Resurfaced clip shows Prince William, 17,  and King Frederik together at the christening of Constantine Alexios of Greece in 1999 - before reuniting at the Euros

When the Prince of Wales and King Frederik X of Denmark chatted at the Euros on Thursday, the pair looked like two old friends reunited.

The royal sat next to one another at the game in Frankfurt today, engaging in joyful conversation as they watched their countries battle it out in group stage matches of the Euros.

And it's a distinct change from a resurfaced clip of the pair from 1999 at the the christening of Constantine Alexios of Greece..

William, 41, and Frederick, 56, both opted for smart looking suits as they attended the match, the Danish king opting for a slightly more casual look with no tie and an open collar shirt. 

Frederik is the three-times great grandson of Queen Victoria, while William is her four-times great grandson, meaning the royals are fourth cousins once removed. 

When the Prince of Wales  (left) and King Frederik of Denmark (right) chatted at the Euros today, the pair looked like two old friends reunited

The pair are pictured in 1999, aged 17 and 31, at Constantine Alexios of Greece's christening

In a clip from 25 years ago, shows William - aged 17 - in his heartthrob era, with a full head of hair and a strong jawline. The video shows William holding the child as he became godfather. 

Frederik, then aged 31,  sports a very nineties buzzcut at the christening of his first cousin once removed.

 Constantine Alexios, now 25, who recently split with socialite Poppy Delevingne, 38, is the son of Pavlos, Crown Prince of Greece and grandson of Queen Anne-Marie of Greece, who is Frederik's maternal aunt. 

Today however, it seemly the pair have swapped haircuts, with the Danish king sporting a full head of hair - while William has suffered from a thinning top. 

William and Frederick are often draw together as having parallel lives, both born as the heir with a younger brother alongside.

The Dane's brother, Prince Joachim of Denmark, is often likened to Prince Harry, who was also the 'spare' to the throne.

Frederik is the three-times great grandson of Queen Victoria , while William is her four-times great grandson, meaning the royals are fourth cousins once removed 

In a clip from 25 years ago, shows William - aged 17 - in his heartthrob era, with a full head of hair and a strong jawline. The video shows William holding the child as he became godfather

The two previously appeared as much younger, but equally dapper versions of themselves when they attended the christening in London in 1999.

Both of the young men have changed a lot since the day they became god fathers to the Greek royal 25 years ago.  William appeared to be wearing his arm in a sling following surgery to fix his broken finger from a rugby match.

Despite the sling, William grinned during the christening while holding onto his new god son.

The prince, who was the hottest bachelor at the time, looked dashing in an oversized suit, bright apple cheeks and his golden hair swept casually from his forehead.

Meanwhile, Frederick, looked handsome with cropped black hair and a short beard. He wore a similar style suit with a light blue tie and a burnt orange tie.

Now, William, who is still familiar with a good suit and clean shaven face, is slightly poorer in hair, but all the more wealthy in wisdom and charm.

The pair are pictured - with Y2K style - in 1999

William and Frederik are both great grandsons of Queen Victoria

The ruddy faced rugby player is no longer with his arm in a sling, but is the new heir, following the death of the Queen which made Charles King in 2022, and subsequently the Prince of Wales

William married Kate Middleton in 2011 and the couple now share three children, George, 10, Charlotte, 9, and Louis, 6.

Today, Frederick still wears rough, rugged looking beard with short hair, though the black has turned to grey and the King is appears much more open with his fashion these days.

The former Prince of Denmark, now the King as on January 2024, is married to Mary Elizabeth Donaldson, an Australian marketing consultant  the prince had met while attending the Olympics just a year after the christening of Constantine Alexios.

William and Frederick shook hands with beaming faces at the Euros on Thursday. The two have changed a lot since they became god fathers to the Greek royal 25 years ago

William appeared to jest with the Danish royal was was pictured grinning during the conversation. William and Frederick are often draw together as having parallel lives, both born as the heir with a younger brother alongside

The two shook hands affectionately during the game. Alongside Frederick and William, other European's royals make-up Constantine's impressive line up of godparents including Victoria, Crown Princess of Sweden and King Felipe VI King of Spain

Prince Constantine Alexios is second child of Crown Prince Pavlos and Crown Princess Marie-Chantal of Greece and their first born son, making him the heir of the Crown Prince and Princess of Greece.

Alongside Frederick and William, other European's royals make-up Constantine's impressive line up of godparents including Victoria, Crown Princess of Sweden and King Felipe VI King of Spain.

The Greek royal family was officially abolished in the 1970s and the family now split their time living between the US and the UK among with other European countries.

Prince Constantine spent the first part of his life growing up in London, attending school and college there before heading to Washington in the US to do his degree.  

At the match on Thursday night, England and Denmark drew 1-1, despite England scoring a goal in the first 18 minutes of the game, they failed to finish on top.

The Euros match was England's second so far in the tournament after winning against Serbia on Sunday, with 1-0.

Meanwhile, Serbia drew 1-1 again in their first match of the Euros against Slovenia on Sunday. 

Prince William has had quite the week of sports after turning out the the Royal Ascot yesterday where he attended the annual races with cousins Zara and her husband, Princess Beatrice and her husband Edoardo Mapelli Mozzi, and Princess Eugenie and her partner Jack Brooksbank