Despite only existing from 1918 to 1945, The Kingdom of Yugoslavia held an impressive royal jewellery collection.
The main branch of the family may have owned the Yugoslavian Emeralds, but I would argue that the junior members of the Karađorđević clan possessed the more magnificent jewels.
In 1923, Prince Paul of Yugoslavia (First cousin to King Alexander) married Princess Olga of Greece and Denmark. This marriage was particularly advantageous to Yugoslavia as Olga was related to almost all the important royal families in Europe. Her father was Prince Nicolas of Greece and her mother had been born Grand Duchess Elena Vladimirovrna of Russia, daughter of the formidable and jewel obsessed Grand Duchess Maria Pavlovna, the Grand Duchess Vladimir.
Elena had received the traditional bejewelled wedding presents due an Imperial Russian Grand Duchess, which included this Diamond Kokoshnik Tiara, rumoured to have been made by Chaumet. She in turn, gifted this Tiara to her daughter Olga on the event of her wedding.
Tragically, King Alexander was assassinated in 1929 and Prince Paul became the regent of Yugoslavia. Due to the retirement of Queen Marie, Princess Olga became the de-facto first lady.
Along with her Boucheron Tiara and her Ruby Olive Wreath Parure, Princess Olga wore her Diamond Kokoshnik for many formal portraits and important international events, including the Coronation ball of George VI
After the fall of Yugoslavia in 1945, Prince Paul and Princess Olga went into exile, but due to Olga’s close relation to other reigning European royals, the tiara was still seen at major events. In 1955, Princess Olga wore her Kokoshnik to her son’s wedding to the Italian Princess Maria Pia of Savoy.
During the Pre Wedding Gala for the Wedding of Princess Sofia to Juan Carlos in 1962, Princess Olga was pictured wearing this Tiara but it appeared to have noticeable gaps in the centre. This had led some to believe that the central hanging diamonds had been sold in order to support the family during their exile.
Once again, thanks to Beth at the History of Famous Jewels and Collections Message Board, it would seem that the tiara had simply been remodelled to make the top half higher.
Following family tradition, Princess Olga gifted the Tiara to her new daughter in law (or at least let her borrow it).
Here she is pictured at the wedding of her cousin, King Baudoin of Belgium in 1960. Its current whereabouts are unknown.