Princess Eugenie is wearing the Queen Mothers emerald Kokoshnik tiara for her royal wedding to Jack Brooksbank.
The princess – who is the youngest daughter or Sarah Ferguson, Duchess of York, and Prince Andrew, Duke of York – chose a green colour theme for her wedding.
And matching the theme beautifully was her tiara, which was in the Queen Mothers collection.
The stunning diamond and emerald Kokoshnik tiara formerly belonged to Queen Alexandra.
It was given to Alexandra, Princess of Wales, as a 25th wedding anniversary gift in 1888 by Lady Salisbury.
The bride arrived at St Georges Chapel in Windsor Castle at 11am for her wedding ceremony, with Princess Beatrice acting as her maid of honour.
It is reported that she had wanted a tiara in the shape of a kokoshnik – which is translated to a cocks comb and is a traditional Russian folk headdress.
The tiara was created by Garrard & Co. It features white gold bars pavé-set with diamonds, with the longest being 6.5 cm (2.5 in).
The showpiece of the tiara is the 93.70-carat emerald, which sits in the centre of three small emerald either side.
Alexandra is said to have sent her aunt, the Grand Duchess of Mecklenburg-Strelitz, a letter reading: The presents are quite magnificent.
When she died in 1925, she gave the tiara to her daughter-in-law, Queen Mary.
Queen Mary later left all of her jewels to the Queen Mother in 1953, known as the Greville bequest, and it was inherited by the Queen when her mother died in 2002.
Eugenie paired the tiara with diamond and emerald drop earrings, which were a gift from her husband for their wedding day.
Sarah Fergusion, who kept to the colour theme with her outfit by wearing a striking bright green jacket and dress, also wore diamond and emerald earrings for the big day.