Following a lunch hosted by the Monarch, members of the royal family, including Queen Elizabeth, Prince Charles and Prince William took part in a procession through the grounds of Windsor Castle.
Watching on was Kate Middleton, wearing a chic Catherine Walker Liza coat dress and matching Lock & Co fascinator, Queen Letizia of Spain in a dress by Spanish label Cherubina, and Queen Maxima of the Netherlands in a blush-pink dress by Dutch designer Claes Iversen.
King Felipe VI of Spain and King Willem-Alexander of the Netherlands were officially invested by the Queen as Supernumerary, or 'Stranger', Knight of the Garter.
Also in attendance was the Duchess of Cornwall, wearing a pale pink Anna Valentine coat dress with a Philip Treacy hat and the Countess of Wessex in a Suzannah dress and Jane Taylor hat