An aristocrat grabbed a burglar by the collar after catching him raiding her stately home.
Lady Sara Bathurst discovered Thomas Trickey hiding behind curtains at her Cirencester Park home, a court heard.
The 54-year-old countess felt terrified, but marched Trickey, 20, to her kitchen and called the police, Bristol Crown Court was told.
Trickey, of Cirencester, admitted burglary with intent to steal and was sentenced to 20 months youth custody.
On Thursday, prosecutor Nicholas Lee told the court the alarm went off at Lord and Lady Bathurst's home shortly after 01:00 BST, on 18 October.
'Devastated by experience'
"On pulling back the curtains she screamed and jumped backwards as she discovered Trickey cowering behind a shelf," Mr Lee said.
"Trickey told her 'I don't mean any harm'. She grabbed him by the collar and took him into the kitchen and called the police."
In a victim impact statement Lady Bathurst, a former High Sheriff of Gloucestershire, told the court she felt "devastated" by the experience.
"My husband and I need to feel safe in our home. He has shattered that illusion," she said.
Joe Maloney, defending, said: "It is obvious he is genuinely remorseful and he put his hands up to the offence when he was arrested.
"He made no attempt to run. He is very sorry for what he has done and regrets what has happened."
Trickey, of Cheltenham Road, Stratton, pleaded guilty to burgling the mansion with intent to steal and was sentenced by the Recorder of Bristol Judge Peter Blair QC.