Prince Harry and Meghan Markle will wed on Saturday at St. George's Chapel in Windsor. Afterwards, soldiers from the Household Cavalry will escort the couple's carriage through the streets of Windsor on horseback. Invitations have been sent to 600 guests, with a further 200 invited to the couple's evening reception.  

Fanfares and final touches. The State Trumpeters of the Household Cavalry are rehearsing for the wedding of Prince Harry to Meghan Markle. And the pressure is on to make sure they hit all the right notes.

MATTHEW SCREEN TRUMPET MAJOR "There shouldn't be any problems. However, I suppose the ultimate buck would stop with me, what would happen? I don't know, maybe the Tower (of London) would be reopened for me, who knows?"

Soldiers from the Household Cavalry will escort the couple's carriage through the streets of Windsor on horseback. The regiment has acted as the monarch's bodyguards for hundreds of years, and are a familiar sight at state occasions like the Queen's birthday parade. Prince Harry served his ten years in the army in the Household Cavalry, and so for those who worked alongside him, May 19th won't be just a normal day at the office.

CORPORAL OF HORSE FRANKIE O'LEARY "I've done many a big parade before. I've been a Household Cavalryman for many years but it's nice to go to anyone's (wedding) who you know is getting married. Wedding's are a wonderful occasion and this one's a little bit bigger than your normal affair, carriages and horses and castles and bands, so I'm very excited."

So preparations are underway at the barracks, with no detail too small. Even the horses are getting new shoes. And it is this meticulousness that the soldiers here believe sets them apart.

CAPTAIN TOM MOUNTAIN ADJUTANT AT THE HYDE PARK BARRACKS "The attention to detail that they have to go into here, the time management and discipline, the maintenance of not only themselves but their horse are all directly transferable to the operational side, and I believe make a better soldier and better household cavalryman."

250 members of the armed forces will play a ceremonial role on the big day, but for these soldiers, this is a professional engagement with a personal touch. And they're making every effort to ensure nothing will take the shine off their former cavalryman's big day.