The King has paid tribute to his “dear cousin” King Harald V of Norway who has died aged 89.
Harald, who Charles’s second cousin once removed, died on Friday morning with his son automatically becoming King Haakon VIII.
In a statement released by Buckingham Palace, the King said: “It is with the most profound sadness that my wife and I have learned of the death of my dear cousin, King Harald V of Norway.
“For 35 years, King Harald served his people with unwavering dedication, guiding Norway through times of great change with warmth and humility.
“As Norway mourns the loss of so towering a figure, my whole family join in remembering a much-loved kinsman and friend whose kindness, compassion and deep sense of duty echoed from across the sea and across the decades.
“The United Kingdom and Norway share particularly close historical and family ties, with Britain one of the first countries to recognise Norwegian independence and establish diplomatic relations in 1905.
“These special bonds were even further strengthened during the dreadful trials of the Second World War and helped to bind our two countries together.
“The Queen and I extend our deepest and most heartfelt condolences to Queen Sonja and all her family, as Britain shares in Norway’s grief at this time of such heartbreaking loss.”
He signed the message: “Charles R.”
The Union flags at Buckingham Palace, Clarence House, Windsor Castle and the Palace of Holyroodhouse will fly at half-mast until 8pm on Friday, the palace said.
A musical tribute to Harald will also be performed at the Changing the Guard ceremony at Buckingham Palace at 11am.
Harald was a second cousin of the late Queen, meaning Charles is once removed.
The oldest European monarch at the time of his death, Harald was crowned after his British-born father, King Olav V, died in January 1991.
Harald was born in 1937 in Asker, near Oslo, and was just three years old when the Nazis occupied Norway at the start of the Second World War.
To avoid capture, Harald and his sisters, Ragnhild and Astrid, fled with their mother first to Sweden and then by boat to the US, while Harald’s father and grandfather went into exile in Britain with Norway’s government.
After being reunited with his family following the end of the war, Harald went on to attend the Norwegian military college and Oxford University.
A keen sailor, Harald represented Norway at the summer Olympics in 1964, 1968 and 1972.
After refusing to marry several noblewomen, he wed his childhood sweetheart Sonja Haraldsen, the daughter of a successful businessman, in 1968 and they had two children – Haakon and his older sister Princess Martha Louise.
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