The Crown Prince made it clear to his father, 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, as 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 29 August 1968, at Oslo Domkirke in Oslo. She thus acquired the style of Royal Highness and the title of Crown Princess of Norway.