Three years before the birth of Princess Helena, he had succeeded to the headship of the House of Schleswig-Holstein-Sonderburg-Glücksburg and the title of Duke upon the death of his father in 1885.

[citation needed] The only activity deemed acceptable for a female member of the royal house except representation was charity and, in 1913, Princess Helena started a campaign to found an orphanage in Gentofte.

[2] One of her own servants, Paul Dall, responsible for setting her table, was a contact of the German Abwehr in Copenhagen, and was after the war judged guilty as a spy.

In 1942, Helena made efforts to convince Prince Knud of Denmark to persuade the monarch to allow Nazi members in to the Danish government.

[3] After the war, owing to Princess Helena being a member of the Royal house, she was not brought to trial, as any punishment was at the discretion of the King.

[3] She was allowed to return to Denmark in 1947, when Prince Harald fell gravely ill. She stayed with her spouse until his death two years later.