This Edwardian-style hotel opened in 1902 as the Hyde Park hotel. It was originally built as Gentleman's Club but there was a fire there.
It was acquired by Mandarin Oriental in 1996 and reopened in May 2000 after a major (GBP57MN) renovation and redesign of the restaurants & bars. The hotel hosted Margaret Thatcher's 80th birthday party and, in 2011, it also hosted the UK Royal Family's pre-Royal Wedding party for the Crowned Heads of State attending Prince William's wedding the next day. I have eaten in 'Dinner by Heston' (Blumenthal) in the hotel, Foliage (when it was in the same space) and Bar Boulud in the basement.