Inside Princess Olympia of Greece's extravagant, star-studded 21st birthday party, complete with A-list guests and a topless party-goer

Princess Maria-Olympia of Greece will be 21 on July 25th and her father Pavlos, Crown Prince of Greece, turned 50 on May 20, so the pair had a joint party on Sunday night and it was a royal affair complete with A-list guests like Paris Hilton, and her sister Nicky Rothschild, Poppy Delevingne, designer Valentino Garavani, heirs to royalty and tycoons. The joint party held in the Cotswolds