King Harald V of Norway died early Friday at the age of 89. The royal household announced that he passed away peacefully at 6:35 a.m. local time at Oslo University Hospital Rikshospitalet.

The king had been hospitalized since August 17 for treatment of haemolytic anaemia and a related bacterial infection. His condition was described as extremely serious in updates from the palace earlier in the week, prompting family members including Queen Sonja and Crown Prince Haakon to remain at his bedside.

Harald ascended the throne in 1991 and served as Europe's oldest reigning monarch. Crown Prince Haakon, 53, had been acting as regent during his father's illness.

Prime Minister Jonas Gahr Støre cancelled a planned trip to Germany in light of the king's health. Crowds gathered outside the royal palace in Oslo to lay flowers as news of his declining condition spread.

The king is survived by his wife, Queen Sonja, and their children and grandchildren. The palace website was updated with the announcement and noted that changes would be made to reflect the succession.