Norway's King Harald V has died at the age of 89, the royal palace in Oslo announced Friday. He passed away peacefully at 06:35 local time at the national hospital, where he had been receiving treatment for a rare blood condition.

The royal flag on the palace roof has been lowered to half-mast following the news. In the 24 hours leading up to his death, members of the royal family visited the king, and crowds gathered at the palace to lay flowers.

Harald, who reigned for 35 years, will be remembered as a popular and reforming figure. He modernized the monarchy, broke with tradition by marrying a commoner, Queen Sonja, and served as a unifying presence for Norway. Royal observers have described him as down-to-earth, respected, and beloved, often referred to as the "grandfather of the nation" and the "People's king."

He is succeeded by his son, Crown Prince Haakon, 53, who will hold an extraordinary council of state with the government on Friday. King Charles III of the United Kingdom sent his "most heartfelt condolences," and King Carl XVI Gustaf of Sweden remembered Harald as "a good friend."

Harald was Norway's first king born in the country since the 14th century. He ascended the throne in 1991. During his reign, the Norwegian monarchy became more egalitarian and transparent, particularly regarding finances and health, according to historian Ole-Jørgen Schulsrud-Hansen. Royal correspondents have noted his closeness to the people, citing his welcoming of the national football team home after their 1994 World Cup quarter-final appearance.

Born on February 21, 1937, Harald's early life was marked by World War II. His mother fled with the children to Sweden, and they later traveled to the United States at the invitation of President Franklin D. Roosevelt. He returned to Norway after the war, completed his education, and served in the military. He became crown prince in 1957 and studied social science, history, and economics.

More recently, the royal family, including King Harald and his wife Queen Sonja, faced health challenges. The monarchy also navigated public scrutiny related to the daughter-in-law Mette-Marit's past associations and a conviction of her son, Marius Borg Høiby.

King Harald is survived by his wife of almost 58 years, Queen Sonja; their daughter Princess Märtha Louise; their son, the new King Haakon; and six grandchildren.