Harald lived in Washington, DC during World War II, but returned to Norway to complete his education at the Norwegian Military Academy and then at Balliol College, Oxford. Harald married a commoner, Sonja Haraldsen, in 1968, a marriage which sparked much public controversy. The couple have two children, Princess Märtha Louise and Crown Prince Haakon Magnus.
An avid sailor, Harald represented Norway in the yachting events in the Olympic Games several times during his Crown Prince years, and carried the Norwegian flag at the opening parade of the Olympic Games in Tokyo in 1964. With his sailing crew he has won world championship bronze, silver and gold medals, in 1988, 1982 and 1987, respectively.
On monday December 1, 2003, King Harald was announced to be suffering of cancer of the bladder. A successful operation where his bladder was removed and a new one constructed took place December 8 at Rikshospitalet University Hospital in Oslo. The King will be on sick leave from all official duties for two to three months. Crown Prince Haakon (Håkon) is the acting regent during King Harald's illness and convalescence.