Now, the waist-defining gown has been rediscovered among the personal belongings of the Hellenic royal family in Tatoi.
Anne-Marie was just 13 when she met Constantine, who joined his parents on a state visit to Denmark. Two years later, in May 1962, their paths crossed once again when Anne-Marie acted as bridesmaid to his sister Sofía and Constantine made his intentions to marry her clear.
King Frederik insisted that his then-sixteen-year-old daughter finish her education before she announced her engagement, which finally became public in 1963. Their wedding had originally been planned for 1965 but the death of Constantine's father King Paul in March 1964 meant he became monarch and their wedding date was moved up.
Anne-Marie, then 18, married King Charles' second cousin and Prince William's godfather, then 24, in September 1964 at the Metropolitan Cathedral of the Annunciation in Athens. Designed by Danish fashion designer Jorgen Bender, her wedding dress featured a bateau neckline, an empire waist, cropped sleeves and a 20-foot train, and it was reportedly paid for by her father the King of Denmark.
The bride teamed the frock with her Princess Margaret of Connaught's Irish lace veil and the Khedive of Egypt tiara. Meanwhile, King Constantin wore his white Field Marshal uniform adorned with his medals, and her bridesmaid Princess Anne donned a white dress with sheer sleeves and a bow at the waist.
The couple went on to host their wedding reception at the Royal Palace of Athens, before setting off for their honeymoon in Corfu. However, Anne-Marie and Constantine only ruled for three years before a military coup saw them spend more than four decades in exile.
The parents – who share five children Princess Alexia, Crown Prince Pavlos, Prince Nikolaos, Princess Theodora, and Prince Philippos – lived in Italy and England before relocating back to Greece in 2013.
While the tiara and veil worn by Anne-Marie were passed down to other royal brides, her wedding dress had not been seen until July, when it was unearthed at the Greek palace of Tatoi near Athens alongside the jewels of the Greek Crown.
Anne-Marie was widowed in January 2023 when Constantine died of a stroke aged 82. His office released an official statement confirming his death which read: "It is with deep sadness that the Royal Family announces that HM King Constantine, beloved husband, father, and brother, passed away yesterday, January 10, 2023, while being treated at 'HYGEIA' hospital in Greece."
At her husband's funeral, Anne-Marie paid tribute to their wedding day by wearing her Crucifix pendant alongside elegant pearls.