The Prince of Wales will represent his father at the funeral of King Harald V of Norway on Wednesday.
Harald, who is the King’s second cousin once removed, died on August 28 at the age of 89.
His funeral will take place at Oslo Cathedral, with mourners including his widow, Queen Sonja.
William will be joined by his aunt, the Princess Royal, who is attending in a private and personal capacity as godmother of the new king, Haakon VIII.
Under royal precedent, the sovereign does not attend funerals of other heads of state.
The duty falls to William, a future king, to represent his father and pay his respects at Wednesday’s service.
Charles paid tribute to his “dear cousin” and “much-loved kinsman and friend” after news of Harald’s death was announced.
In a statement released by Buckingham Palace, he said the monarch served the people of Norway with “unwavering dedication” and guided them through times of change with “warmth and humility”.
The late Queen Elizabeth II and King Harald were second cousins and shared the same great-grandparents, King Edward VII and Queen Alexandra.
William and the now-Princess of Wales carried out an official tour to Norway in 2018.
They dined with King Harald and Queen Sonja at the Royal Palace, where Harald described them as “family” and praised their support of the late Queen.
The Norwegian sovereign arrived at the banquet arm in arm with pregnant Kate, who was expecting Prince Louis and wearing a flowing Alexander McQueen gown, with the gesture mirrored by his wife Queen Sonja and William who walked behind them.
William and Kate also spent time visiting the ski slopes with the then-Crown Prince Haakon and Crown Princess Mette-Marit, now the new King and Queen.
William represented his father at the funeral of Pope Francis in the Vatican in April last year.
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