Norway’s King Harald V has died at the age of 89, the Royal Palace announced. He passed away peacefully at Oslo University Hospital on Friday, August 28, at 6:35 a.m. local time.

King Harald had been hospitalized since August 17 and was receiving treatment for a rare blood disorder. His condition later worsened after a bacterial infection in his bloodstream.

Harald became king in 1991 and remained Norway’s head of state for more than 35 years. He was widely known for his modest personality, close connection with the public and efforts to promote national unity.

Following his death, his son Crown Prince Haakon succeeded him and became King Haakon VIII. Haakon had already been carrying out royal duties as regent while his father’s health deteriorated.

The Norwegian royal flag was lowered following the announcement as the country entered a period of mourning.