Soldiers from 27 Regiment Royal Logistic Corps have begun public duties in London and Windsor.
Around 80 troops were selected to support the Grenadier Guards in ceremonial duties between May and July.
They include mounting the Queen's Guard and the Windsor Castle Guard and acting as ambassadors for their regiment and for the nation.
Until 17 May, however, their public duties are limited by coronavirus restrictions.
27 Regt RLC, not typically known for its drills, passed a 'fit for role' test last month.
Personnel are taking on some of the most prestigious royal ceremonial duties, including roles at Buckingham Palace, Windsor Castle, St James's Palace and the Tower of London.
Speaking to Forces News in April, Lance Corporal Abbie Pratt said: "From February to now, it's been non-stop, long nights, long days, we've all got through it, and it's got us to where we are now, it's a big achievement."
Last year, the regiment was deployed on Operation TOSCA - peacekeeping duties in Cyprus.
It also supported the NHS on Operation RESCRIPT – the name for the military response to the COVID-19 pandemic in the UK.