Prince Nikolaos of Greece and Tatiana Blatnik married in a joyous ceremony on Wednesday just as the sun was setting over the Mediterranean.
Royals from across Europe, including Spain's Queen Sofia and Princess Mary of Denmark, witnessed the happy occasion on the island of Spetses, a three-hour boat ride from Athens.
Nikolaos, 40, the second of King Constantine's three sons, had been dating 29-year-old Tatiana, an events planner for Diane von Furstenberg for six years.
Though the Greek royals were deposed in 1974 – hundreds of well wishers thronged to share the excitement at the monastery of Ayios Nikolaos, which was decked out with national flags.
For her big day, the bride arrived in a traditional horse-drawn carriage, wearing a strapless ivory gown, a full-length veil and a tiara belonging to her husband's family.
She was escorted up the aisle by her stepfather Attilio Brillembourg.
Following their marriage she is now styled HRH Princess Nikolaos of Greece and Denmark - because her new father-in-law is descended from the northern country's King Christian IX.