The Prince of Wales will attend the funeral of King Harald V of Norway on Wednesday in Oslo, Buckingham Palace has announced.
Also going to the funeral, in a personal capacity, is Princess Anne, who is godmother to Norway's new monarch, King Haakon VIII.
The late King Harald, a popular, modernising figure who had been on the Norwegian throne for 35 years, died last month at the age of 89.
Royal sources say Prince William's attendance, representing his father King Charles, follows the convention that the monarch does not usually go to the funeral of another head of state.
Large crowds are expected for the farewell to King Harald on 9 September, with a funeral procession to be followed by a service at Oslo Cathedral.
Thousands have queued to pay their respects to the late king, during his lying in state in the chapel of the Royal Palace in the Norwegian capital.
At the funeral, alongside Prince William, will be the widowed Queen Sonja, members of the Norwegian royal family including new King Haakon VIII, and other European royals.
The service will be followed by a private burial in Norway's royal mausoleum in the Akershus Fortress.
Among the tributes to King Harald was an emotional televised speech by his son King Haakon, who said: "Thank you for being such a good dad."
Harald had been seen as a down‑to‑earth "people's king" who helped modernise the monarchy, notably marrying a commoner and serving as a unifying figure.
His son said he represented the values of a society built on law and justice, where everyone is of equal value.
King Charles's message praised his cousin King Harald for serving his people with "unwavering dedication, guiding Norway through times of great change with warmth and humility".
