Her Majesty's Representative at Ascot

The holder of the unique British royal household post of His or Her Majesty's Representative at Ascot heads the Ascot Office at St. James's Palace and is responsible for admitting people to the Royal Enclosure at Ascot Racecourse.

Until 1901, the position was held by the Master of the Buckhounds. Since then, the incumbents nominatim were:

...
Wikipedia