On March 21st 1929 the then Crown Prince Olav of Norway (future King Olav V) married his cousin Princess Martha of Sweden.
Olav was the only child born to King Haakon VII of Norway he was born Prince Carl of Denmark a son of King Frederick VIII of Denmark and his wife Princess Louise of Sweden. Olav’s mother was Princess Maud of Wales a daughter of King Edward VII of the United Kingdom of Great Britain and Ireland and his wife Princess Alexandra of Denmark, herself a sister of King Frederick VIII of Denmark.
While Martha was one of four children born to Prince Carl.of Sweden, Duke of Västergötland a son of King Oskar II of Sweden and his wife Sophia of Nassau, her mother was Princess Ingeborg of Denmark a daughter of King Frederick VIII of Denmark making her the sister of Olav’s father Haakon.
Their marriage would last twenty five years until Martha’s death in 1954, Olav survived her by thirty seven years dying in 1991 aged eighty seven he never remarried despite being fifty one when he was made a widower.