Members of Inkerman Company came from their base at Aldershot to Boscobel House and The Royal Oak recently also as a physical test as they build towards deploying on operations to Iraq at the end of the year.
Troops are still in Iraq as part of a global coalition working to help defeat Daesh, also known as Islamic State.
More than 60,000 Iraqi Security Forces members have now been trained by British soldiers who have played their part in contributing to a stable, prosperous and united future for Iraq.
A spokesman for the English Heritage site said it was the first time in 366 years that the company had been back to the site of their unit's creation.
They marched in to the tune of ‘Grenadiers Return’ played by a drummer and flute player from the Corps of Drums, and as they entered applause sounded around the courtyard.
Site manager Daisy Lambert and Boscobel staff presented the Inkerman Company with an oak sapling supplied by English Heritage that will be planted at their barracks for future grenadiers to look after and watch grow.
The Inkerman Company was name after a battle in the Crimean war. But it is a direct descendant of Wentworth’s Regiment of Foot. It formed around King Charles II who took refuge at the Boscobel site in 1651 after fleeing for his life following Civil War defeat.
Colonel Careless, who had hidden with the King in the Royal Oak, was among the first officers of the regiment. This link is recognised in the company colour – which features a picture of Charles II framed in the Royal Oak on a crimson background.
Following the execution of King Charles I in 1649, his eldest son made an attempt to regain the throne.
In 1651 his hopes were crushed at Worcester in the final conflict of the Civil War.
Following the defeat, young Charles was forced to flee for his life towards the River Severn. Finding his way blocked by Cromwell's patrols he sought refuge instead at Boscobel, hiding first in a tree, which is now known as The Royal Oak.
During their visit, the troops also posed with Maureen, the site's own Shropshire Ewe, which is cared for by the site team.
Boscobel House is a picturesque hunting lodge close to the Staffordshire border.
There is also a descendant of the oak tree in which King Charles hid for a day as Cromwell’s soldiers searched for him below.
Boscobel has a history of being a thriving Victorian farm, and visitors can meet the resident farm animals in the historic stables, barns, and dairy.