Crown Prince Harald got engaged to Sonja Haraldsen in March 1968. They had been dating for nine years, although this had been kept secret because of opposition to her non-royal status. The Crown Prince made it clear to his father, then King Olav V, that he would remain unmarried for life unless he could marry her. This would in effect have put an end to the rule of his family and probably to the monarchy in Norway; he was the sole heir to the throne. Faced with having to choose one of his relatives from the Danish Royal Family, the Dukes of Schleswig-Holstein or even the Grand Dukes of Oldenburg as his new heir in place of his son, Olav V consulted the government for advice and the result was that the couple were wed on August 29th, 1968, at Oslo Domkirke in Oslo. She thus acquired the style of Royal Highness and the title of Crown Princess of Norway. To watch the video of their wedding, click here.