The splendid diamond necklace once belonged to Queen Olga of Greece who was born a daughter of Grand Duke Konstantin Nikolayevich of Russia, himself a son of Tsar Nicholas I of Russia. When she was sixteen years old she met the young Danish-born King George I of Greece during his trip to Russia to meet with his sister Dagmar, the Danish wife of Tsar Alexander III. Olga and King George I fell in love and married in 1867. It is possible that the diamond necklace was one of her wedding presents as the time and splendour seems to be appropriate.
Their oldest son, Constantine I of Greece, succeeded as King upon his father's assassination in 1913. He left Greece on 11 June 1917 as he had to abdicate, went into exile in Switzerland. He was succeded by his second son Alexander as acting King. When Alexander died on 25 October 1920 following a monkey bite, Queen Olga acted as Regent until Constantine returned from exile as King on 19 December 1920 to reign a second time.
Queen Olga involved herself extensively in charity work and oversaw the building of Greece's largest hospital in Athens. Her open-mind and kindness made her Greece's most popular Queen.
Queen Olga gave the diamond necklace to her granddaughter Princess Olga of Greece and Denmark - probably on the occasion of her wedding with Prince Paul of Yugoslavia in 1923, three years before Queen Olga's death.