The princesses were part of a large royal party, which also included their dad Prince Andrew, as the family began the weekend of fun to mark 60 years on the throne for the Queen. Their mother, Sarah Ferguson, the Duchess of York, even Tweeted: "So proud of my of my beautiful daughters and how special to be at the Epsom Derby supporting their Granny what an amazing Grandmother the Queen is."
Joined by husband Prince Philip, 90, the Queen, 86, wore a royal blue coat and white silk dress with floral detail by Stewart Parvin, and a hat by Rachel Trevor-Morgan. The couple was driven down the Epsom Racecourse in Epsom, Surrey, in a State Bentley to the cheers of flag-waving race fans.
Then, Dancing with the Stars alum and classical singing star Katherine Jenkins serenaded Her Majesty. Jenkins, who was accompanied by the Band of the Royal Marines, lead many of the 130,000 strong crowd in a rendition of "God Save The Queen."
Jenkins wore a Suzanne Neville gown to perform before changing into a blue Roland Mouret dress, Philip Treacy hat, and shoes by Jimmy Choo.
Sunday the Jubilee continues with a festival of 1,000 boats and more of the royal family making a pageant along the River Thames. Check back for more fun details and photos!