King Frederick of Denmark unveils new signature as monarch, including one important detail, just like that of King Charles

King Fredrik of Denmark has unveiled his new signature – and it shares an important detail with King Charles'.

The royal, 55, took the throne earlier this month when his mother, Queen Margrethe, abdicated and ended her 52-year reign.

Earlier this week, the official Instagram account of the Danish royal family posted a photo of a 100th birthday card signed by the new king.

They captioned the post: 'In a small town in North Jutland, a 100-year-old birthday boy today is the first to receive a congratulations from His Majesty the King.'

The post further explained how King Frederick has decided to continue this tradition of sending cards to the public celebrating their 100th, 105th and 110th birthdays.

Moreover, King Frederik also reiterated how he will send his congratulations to couples celebrating their 60th, 65th, 70th and 75th wedding anniversary.

In addition, the Danish royal family posted a photo of the birthday card, which was printed on white paper and featured their code.

Under the printed congratulatory message, King Frederik made his first debut since becoming the official monarch.

Like King Charles, the monarch signed his name with an 'R' for 'Rex', which is Latin for king.

Although Queen Mary's new signature has not yet been revealed, she will likely also use 'R', just like Queen Camilla.

In September 2023, King Charles and Queen Camilla signed birthday cards for Britain's oldest living man and woman. John celebrated his 111th birthday this summer while Ethel turned 114.

Shortly after the Queen's death in September 2022, Buckingham Palace unveiled the new Royal Code – which features the initials of the King's name Charles and the King's title Rex, as well as the Roman numeral III.

Earlier this month, the Danish royal family shared an intimate and telling behind-the-scenes look at King Frederick's proclamation.

Earlier this week, the official Instagram account of the Danish royal family posted a photo of a 100th birthday card signed by the new king.

In September 2023, King Charles and Queen Camilla signed birthday cards for Britain's oldest living man and woman (pictured)

Queen Margrethe signed her historic abdication papers alongside her son and grandson Prince Christian, 18, present at Christiansborg Palace in Copenhagen.

The Queen's last words before leaving the Council of State were: 'God save the King.'

After this, the new king addressed the crowd that had gathered outside the royal palace from the balcony.

Harrowing behind-the-scenes footage on the Danish royal family's Instagram page shows the moment Frederik nervously approached the balcony to make his first public appearance since becoming king.

The father of four – wearing his military regalia – took a deep breath as he looked to an aide for permission to walk onto the balcony.

Pictured: Queen Mary, 51, pictured clinging to her daughter, Princess Josephine, 16, who looked pretty in a black coat and pearls

The footage then jumps to Queen Mary walking out to the balcony to wave to the crowd of royal fans with her husband

King Frederick's younger brother Prince Joachim – whose children were stripped of their royal titles last year – looked pensive as he watched the emotional balcony scene from the palace.

From the palace you can see Queen Mary, who was dressed for the occasion in an elegant white dress by Soeren Le Schmidt, clinging to her daughter Princess Josephine.

The 13-year-old looked suitably smart in a black jacket with gold buttons and her hair half up, half down and secured with a bow.

As Prince Christian stood behind his mother and siblings, 16-year-old Princess Isabella – who wore a red coat – lovingly placed her hands on the shoulders of her younger brother, Prince Vincent.

The footage then jumps to Queen Mary walking out to the balcony to wave to the crowd of royal fans with her husband.

The couple appeared overcome with emotion as they shared a loving look before being joined by their four children.

From the palace, King Frederick's younger brother Prince Joachim – whose four children were stripped of their royal titles in January 2023 – thoughtfully took in the scene unfolding on the balcony.

The royal, 54, attended the ceremony without the support of his wife Princess Marie and their two children, Count Henrik, 14, and Countess Athena of Monpezat, 11.

After Queen Margrethe stripped her grandchildren of their royal titles, Joachim and his second wife moved with their children to Washington DC – where the royal family works as a defense industry attaché at the Danish embassy.