Items of the Mounted Review Order are polished at Hyde Park Barracks on April 15, 2011 in London, England. (Photo by Dan Kitwood/Getty Images)

Organist and Master of the Choristers James O'Donnell (R) conducts The Choir of Westminster Abbey, who will sing at the Royal Wedding perform at Westminster Abbey on April 15, 2011 in London, United Kingdom. (Photo by Dominic Lipinski - WPA Pool/Getty Images)

Flags line The Mall leading to Buckingham Palace on April 15, 2011 in London, England. The Mall makes up part of the route that the HRH Prince William and Catherine Middleton will take when they marry two weeks today. (Photo by Dan Kitwood/Getty Images)

FLC oH, Farrier Lance Corporal of Horse, Chris McCabe fire welds a horse shoe in the forge at Hyde Park Barracks on April 15, 2011 in London, England. (Photo by Dan Kitwood/Getty Images)

Ceremonial helmets of the Household Cavalry on display at Hyde Park Barracks on April 15, 2011 in London, United Kingdom. (Photo by John Stillwell - WPA Pool/Getty Images)

Blossom and spring flowers bloom in front of Buckingham Palace before the Royal Wedding on April 15, 2011 in London, England. (Photo by Matthew Lloyd/Getty Images)

State Trumpeters perform in the parade square at Hyde Park Barracks on April 15, 2011 in London, England. (Trooping the Colour) in June. (Photo by Dan Kitwood/Getty Images)

A horse is groomed in the stables at Hyde Park Barracks on April 15, 2011 in London, England. (Photo by Dan Kitwood/Getty Images)

The Lifeguards of the Household Cavalry are prepared for inspection at Hyde Park Barracks on April 15, 2011 in London, England. (Photo by Dan Kitwood/Getty Images)