Gartree Prison, near Market Harborough, got the Royal seal of approval with a visit from Princess Anne last week.
The Princess Royal spent nearly two hours at the prison chatting to staff, in her role as patron of The Butler Trust.
Gartree’s custodial manager Darren Walls called the visit “great for the service and for the jail as a whole”.
And acting deputy governor Bill Newton said it was a fantastic occasion which had visibly boosted staff morale.
But a big reason for Princess Anne’s visit was the prison’s Butler Trust award-winner – support worker Claire Morgan.
The trust was set up in 1985 to celebrate outstanding practice by people working in the prison service.
It does this through an annual award scheme, with a ceremony held at Buckingham Palace.
Butler Trust director Simon Shepherd explained: “The Princess Royal presents the awards, and then tries to visit as many award winners as she can during the year.
“People who work in prisons do a difficult job and rarely get any thanks.”
Princess Anne met Claire, who was commended for her “extraordinary” work by The Butler Trust in the 2013-14 awards at Buckingham Palace.
Claire runs ten workshops for prisoners, from computing and sewing to the construction of wooden planters, sold at a local garden centre.
Claire said: “I try to gain a clearer understanding of the daily struggle that these individuals in Gartree are going through.”
Princess Anne, daughter of the Queen, arrived at Kibworth Golf Club by helicopter last Thursday, before being taken by car under a police escort to the prison.
Gartree Prison governor Ian Telfer, Butler Trust trustee and former Gartree Governor Bob Perry, and Mr Shepherd were presented to The Princess Royal by the Lord Lieutenant of Leicestershire, Lady Jennifer Gretton.
Then, over the next two hours, about half of the prison’s staff got the chance to meet Princess Anne.
The Princess visited Gartree’s restaurant Flavours, a therapeutic community unit for Gartree prisoners with learning difficulties and the Psychologically Informed Planned Environment (PIPE) therapeutic centre.
Dozens more staff then met The Princess Royal at a reception in the chapel.
Head of security Colin Martin presented the Princess with a stuffed owl and pussycat toys, made by prisoners.
The toys were the first two to come off a prison workshop production line.
The toys are now being sold at London’s Fortnum & Mason store.
In nearly 30 years as The Butler Trust’s patron, The Princess Royal has made about 180 visits to British prisons.
Governor Mr Telfer said it was obvious the Princess “really knows, really cares about, and really understands” prison work.
Category B prison Gartree is home to more than 700 prisoners and only holds “lifers” from across the country.
It has received a series of awards in recent years, including a Leaders in Diversity award for equality, an Investors in People award for people management and a Health and Wellbeing gold award.
The Princess Royal made a previous visit to Gartree Prison in 2006 to officially open its H wing.