A guardsman reportedly passed out on Monday (16.05.16) while rehearsing for Trooping the Colour.
A gentleman had be to carried from Horse Guards Parade near London's St James' Park on a stretcher after he seemingly collapsed while practicing for the lavish annual event, held on June 11 to mark the monarch's birthday.
The parade, which will see 1,400 officers, 200 horses and 400 musicians take part, extends from Buckingham Palace to Horse Guards Parade and back again.
During the ceremony, Elizabeth will be greeted by a Royal salute and will carry out an inspection of the troops, before joining the other members of her family on the balcony of Buckingham Palace for a fly-past by the Royal Air Force.
Trooping the Colour is just one of the many displays put on to celebrate the monarch's birthday as she'll also have a Service of Thanksgiving and a huge street party in London.
Her official birthday fell on April 21 but she was also treated to a horse extravaganza at Windsor Castle in Berkshire as part of a belated celebration over the weekend.
Elizabeth arrived at the royal residence with her husband Prince Philip in the horse-drawn Scottish state carriage, before she took her seat and watched 900 horses - 10 for each decade of her life - prance around the grounds.
The monarch had a beaming smile plastered across her face as she watched performances from the likes of James Blunt, Gary Barlow, Beverley Knight and Kylie Minogue.
Katherine Jenkins delivered the patriotic song 'I Vow to Thee My Country', while a choir version of the coronation anthem 'Zadoc the Priest' filled the stunning grounds.
The Earl of Wessex, his daughter Lady Louise and the Princess Royal also treated the queen to a special surprise as they appeared at the show on three of her ponies in the grand final, ahead of the speculator fireworks display.
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