His Danish Majesty's Yacht Dannebrog (A540) was launched by Queen Alexandrine at Copenhagen in 1931, and commissioned on 26 May 1932. The yacht now serves as the official and private residence for King Frederik X, and members of the Royal Family when they are on official visits overseas and on summer cruises in Danish waters. When at sea, the Royal Yacht also participates in surveillance and sea-rescue services.

A royal yacht is a ship used by a monarch or a royal family. If the monarch is an emperor the proper term is imperial yacht. Most of them are financed by the government of the country of which the monarch is head. The royal yacht is most often crewed by personnel from the navy and used by the monarch and their family on both private and official travels.