They were last in action at their home, Woolwich Barracks, where they fired a 41-gun salute to mark the death of His Royal Highness.
On the day of the funeral they will be firing the processional minute gun.
The funeral procession will set off from Windsor Castle’s Quadrangle to its St George’s Chapel to the sound of one of those three guns roaring out over the Berkshire countryside.
The guns will continue to fire on the stroke of each minute each until the procession arrives at the chapel.
Asked how is the troop feeling about Saturday’s funeral ceremonies Commanding Officer Major Vicky Flood replied, “At the moment the officers and soldiers are simply focussed on getting everything ready for Saturday, making sure the rehearsals go well.
"I think the enormity of it all will probably hit home after we are back home in Woolwich.”
Moving 39 horses, the guns and all the ceremonial paraphernalia would ordinarily be considered something of a logistical challenge; however, this particular unit is very used to having to ‘forward mount’ - that’s military speak for working away from home base!
“The soldiers are very swept-up, very organised and it won’t surprise you to know there is a lot of military precision that goes in to it.
"We have an advance party that goes to wherever we are moving to so that all the horses bedding and food is sorted.”
Of the 39 beautiful horses belonging to the King’s Troop Royal Horse Artillery, it is Brian that has the not insignificant task of being the Commanding Officer’s mount.
This will be the nine-year-old’s third parade and second as the CO’s horse.
Speaking on whether the horses feel any sense of this occasion, Vicky said “I wouldn’t say they sense the huge occasion coming up, but they certainly know something is different.
"Horses are very much routine animals; they know it is different as they don’t normally come to Combermere Barracks here in Windsor ; whether they are aware of the enormity of it - I’m not sure.”
For Gunner George McDonnell, Saturday’s processional gun salutes will be something of an eye opener for him as it is his fist ceremonial duty, and what a first!
His role is a centre driver, meaning he controls the two middle horses behind the lead driver. He said, “This is my first ceremonial job and it’s a bit surreal at the moment.
"It is such a sad reason why we are doing the salute. It is obviously not the same as the Queen’s Birthday Parade or a joyous occasion and is deeply saddening to everyone that we are doing this salute.
"My personal preparation has been making sure my blues (uniform) is well turned out so I’m immaculate. The horses go through something similar.
"They are clipped so they have a fresh clean coat of hair and are groomed regularly which we call a ‘Salute Groom’.”
With a sense of emotion building, Gunner George McDonnell went on to say, “On Saturday when we fire the guns there is going to be an overwhelming feeling of sadness because that is when I think it will hit us as to why we are firing the guns.”