The Royal Regiment of Fusiliers has been celebrating its 50th anniversary at its headquarters at the Tower of London.
To mark the occasion, Fusiliers have been granted special permission to guard the Tower for 48 hours.
This is the first time for them in eight years, and it's a special permission granted only because of their celebration.
But precision for these events takes practice, and the Fusiliers didn’t have a lot of time to get it right.
Lieutenant Colonel Jeremy Lamb, Commanding Officer of the First Fusiliers, explained that a few soldiers that are now on guard have just returned from Ukraine:
"Although they have been trying to rehearse in their spare time, the last week has been pretty hectic with tailoring, fitting and drill rehearsal and inspection.
Ideally it would have taken quite a lot longer, but as it was we managed to get these guys ready in seven days!"
They marched in front of their Commander in Chief, the Duke of Kent, who was here to attend a Thanksgiving Service at the Royal Chapel.
The guests were then led to the Fusilier’s Regimental Headquarters.
Last month, the Regiment was honoured with the naming of a Virgin Trains Class 91 locomotive to mark the anniversary.
The Royal Regiment of Fusiliers is an English infantry Regiment in the British Army, formed from four historic Fusilier Regiments in 1968.
Since then, the Fusiliers have seen service across the world in Northern Ireland, Cyprus, the Balkans, the 1st and 2nd Gulf Wars and Afghanistan.
The Regiment has two battalions – First Fusiliers in Tidworth and Fifth Fusiliers in Newcastle – and both adapt readily to challenging scenarios.