The British monarch and her husband the Duke of Edinburgh watched as Torchbearer Gina Macgregor, 74, carried the Flame into the castle?s grounds, where she was met by London 2012 chairman Seb Coe.
The day began in Oxford where athletics legend Sir Roger Bannister was the first Torchbearer of the morning, carrying the Flame on the site of his greatest sporting achievement ? the Iffley Road track where he became the first athlete to run a mile in under four minutes, on 6 May 1954.
Later, five-time Olympic gold-medallist Sir Steve Redgrave carried the Flame one-handed while rowing in an eight-man boat on the River Thames, while the afternoon saw the Torch Relay visit Ascot racecourse, where 2,000 Olympic heptathlon champion Denise Lewis handed the Flame to jockey Frankie Dettori.
Other Torchbearers on the day included celebrity chefs Heston Blumenthal and Raymond Blanc, and former England footballer Ray Wilkins, while an Evening Celebration was held at the Madjeski Stadium in Reading, where fans were entertained by British rock band Young Guns.
Find out more about the London 2012 Olympic Torch Relay Presenting Partners.
Find out more about the London 2012 Olympic Torch Relay