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 with a '5021 revolution' theme, marking their two ages (50 years and 21 years). Royalty, socialites, fashionistas and the cream of society were present for the grand event. India Hicks, the granddaughter of Earl Mountbatten of Burma and one of Princess Diana's bridesmaids, attended the royal event and she said guests were asked to 'revolutionize' their black tie ensembles for the party. This meant attendees turned up in beautiful designer gowns but accessorised with some very unexpected pieces.

Indie Kicks herself wore absolutely nothing on top and only painted a tuxedo shirt onto her naked body, making her one of the most scandalously dressed guests. Celebrant Olympia wore a head-turning Steven Khalil dress for the occasion and she 'revolutioned' her look with a metallic fascinator and Gucci platform sneakers. Her cousin and frequent travel companion Talita von Furstenberg (Diane von Furstenberg's granddaughter) wore a sweeping polka dot number with a feathered fascinator. Olympia's mom Marie-Chantal wore the most eye-catching headdress of all; a huge ring of silver stars, making her easy to spot in the crowd.

More photos below.