Crown Prince Christian of Denmark Steps Out for First Time as Heir Following Queen Margrethe's Abdication

Crown Prince Christian is now the 18-year-old heir to Denmark's throne.

On Sunday, Queen Margrethe signed a declaration of her abdication after a 52-year reign, and King Frederik acceded to the throne. The shift in the line of succession means that the new monarch's eldest son is now heir and known as Crown Prince Christian (after being previously known as Prince Christian).

Crown Prince Christian was in the room when his grandmother made her step down from the throne official. As she stood up, Christian handed Queen Margrethe her walking cane. His father, King Frederik, then took the spot at the head of the table.

He then joined his parents, King Frederik, 55, and Queen Mary, 51, and his three younger siblings at the proclamation on the balcony of Christiansborg Castle on Sunday.

In October, Christian turned 18 with a grand celebration to mark the milestone. A gala dinner at Christiansborg Palace gathered royals from around the world, including some fellow future monarchs. He posed for a group photo with future queens Princess Estelle of Sweden, Princess Ingrid Alexandra of Norway, Princess Catharina-Amalia of the Netherlands and Princess Elisabeth of Belgium.

In his first public speech at the birthday gala, Prince Christian said, "I would like to thank everyone who helped celebrate me. Both you who are here and all of you who have sent greetings and gifts. I will never forget today. But maybe I will remember it as less challenging already tomorrow. I have to find my way, even if it leads to a familiar place. I have roots in many places in the world, and I enjoy traveling. But home will always be here. Because I love my country."

Around the time of the birthday milestone, Queen Margrethe also awarded her grandson with the Order of the Elephant, Denmark's highest honor of chivalry.

Although he is now heir to the throne, Crown Prince Christian will likely complete his studies and possibly military training before taking on royal duties full-time. Over the summer, the Danish Royal House announced that Prince Christian wouldn't be taking the government funding he is entitled to by law when he turns 18.

“His Royal Highness Prince Christian turns 18 on 15 October 2023,” courtiers said in a statement on Instagram, posting the prince’s cypher. “Prince Christian's main priority in the coming year will be the completion of the Prince's upper secondary education. In continuation of this, the Royal Palace will provide information on Prince Christian's further youth and education courses when the time is right.”

They said the issue would be revisited when he turned 21 or if there was a change of throne, so there may be conversations now going on behind the scenes about Christian's role.

Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more!

Queen Margrethe, 83, became monarch on Jan. 14, 1972, following the death of her father, King Frederik IX, making her reign exactly 52 years. Her abdication came after she announced her shocking decision to step down during her New Year's speech.

"In February this year, I underwent extensive back surgery. Everything went well, thanks to the competent health personnel, who took care of me. Inevitably, the operation gave cause to thoughts about the future — whether now would be an appropriate time to pass on the responsibility to the next generation. I have decided that now is the right time," she said, per an English translation of the official speech transcription. "On 14 January 2024, 52 years after I succeeded my beloved father, I will step down as Queen of Denmark. I leave the throne to my son Crown Prince Frederik."