Prince Joachim has begun his new job in Washington D.C. following his move to the US with Princess Marie and their two children.
The Danish royal palace shared photographs as the royal, 54, arrived for his first day at the Danish Embassy, where his role is Defense Industry Attaché.
Prince Joachim, who is Queen Margrethe's youngest son, will "help strengthen Denmark's defense industrial cooperation with the United States and Canada in the coming years".
The family's move to America from France was announced by the palace back in March. Prince Joachim's previous role was at the Danish Embassy in Paris.
Prince Joachim and French-born Marie have two children – Count Henrik, 14, and Countess Athena, 11.
The couple are believed to have spent some of the summer at the Danish royal family's private residence, Château de Caïx near Cahors in the south of France, with Joachim's eldest son, Count Nikolai, sharing some snaps from his break on Instagram.
Joachim has two sons from his previous marriage to Alexandra, Countess of Frederiksborg – Count Nikolai and Count Felix, who turned 24 and 21 respectively earlier this summer.
Student Nikolai has already begun his semester at the University of Technology (UTS) in Sydney, Australia and was among the royal guests at the Women's World Cup final.
Queen Margrethe stripped Joachim's four children of their royal titles, in a shock move that was announced last year.
The decree, which came into effect on 1 January, meant that Nikolai, Felix, Henrik and Athena are now titled Count of Countess of Monpezat, instead of Prince or Princess.
The decision caused major upset within the family – with Margrethe later taking the unprecedented step of apologising to her grandchildren.
Crown Prince Frederik, 55, is heir to the Danish throne, followed by his and Crown Princess Mary's four children, Prince Christian, 17, Princess Isabella, 16, and 12-year-old twins Prince Vincent and Princess Josephine.
The Danish royals are set to come together for a special gala dinner for Prince Christian's 18th birthday on 15 October at Christiansborg Palace in Copenhagen.
Learn more about the monarchies of Europe in the clip below...