Dormer — who also starred in The Tudors, featuring some of the real-life royals’ ancestors — attended the annual event to hand out a trophy in the first race.
The award came after the traditional carriage ride onto the course, led by the Queen, 93. Joining her were several members of her family, including Princess Eugenie, 29, who is also giving out a trophy but in the second race.
In that contest, the Queen has a horse named Eightsome Reel competing.
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Yesterday, the Queen’s youngest son, Prince Edward. and his wife Sophie, Countess of Wessex celebrated their 20th wedding anniversary at the racecourse. The couple only live only a few miles away at the magnificent mansion, Bagshot Park.