Prince Philip was in the stands at the Olympics equestrian arena today, cheering on hus granddaughter, Zara Phillips, the 13th in line ot the throne who today made her Olympic equestrian debut.Zara's mother, Princess Anne, was in the VIP seats with Philip at Greenwich Park as Phillips competed in the eventing dressage competition.She said afterwards: 'It was incredible, an amazing feeling to be part of the Olympics and to ride for your country and to just be here. The crowd are amazing.'It was incredible to be selected, and to be at here at home for the Olympics is an amazing feeling. You try to do your best for the team.'The eventing competition runs over several days. As of now, Australia has taken an early lead with Germany and the United States close behind.