Princess Victoria of the United Kingdom wears her sister Maud’s diamond and pearl tiara for the coronation of their parents, King Edward VII and Queen Alexandra, August 1902; more on the tiara over here!
Princess Louise, Duchess of Fife wears her diamond forget-me-not tiara (and her diamond fringe in necklace form) for the wedding of the future King Gustav VI Adolf of Sweden and Princess Margaret of Connaught, June 1905; more on the tiara over here!