Prince Bertil, Duke of Halland, was a member of the Swedish royal family. He was the third son of King Gustaf VI Adolf and his first wife, Princess Margaret of Connaught, as well as the uncle of King Carl XVI Gustaf of Sweden. From 1973 to 1979, he was heir presumptive to his nephew Carl XVI Gustaf and the Swedish throne.

The Swedish royal family since 1818 has consisted of members of the Swedish Royal House of Bernadotte, closely related to the King of Sweden. Today those who are recognized by the government are entitled to royal titles and styles, and perform official engagements and ceremonial duties of state. The extended family of the King consists of other close relatives who are not royal and thus do not represent the country officially.