A vulnerable missing man was forced to work 15-hour days with no pay for 13 years, a trial has heard.
Darrell Simester was found living in squalid living conditions on a farm in south Wales last year.
Cardiff Crown Court was told he slept in a rat-infested shed for more than a decade with just his horse manure-stained clothing for bedding - before being moved to a squalid and cold caravan with a broken door.
A jury heard the 44-year-old regularly washed himself in an animal's feeding trough and used a broken outdoor toilet that would only flush with a bucket of water and a stick.
Prosecuting counsel John Hipkin QC said when Mr Simester was eventually tracked down by his worried family from Kidderminster they found him in a "horrific state" and virtually unrecognisable.
Doctors later found him in poor health - with a chest infection, a hernia and badly calloused feet.
Father and son Daniel Doran, 67, and David Dan Doran, 42, both deny a charge of forcing someone to carry out compulsory labour.
But Mr Hipkin said there could little doubt that Mr Simester was anything but a free man.
He said: "Darrell Simester was a man of timid disposition who for 13 years was forced to work against his will and under menace.
"A local police officer who entered his caravan said it looked as if it had been simply left to rot... and considered it to be unfit for human habitation.
"While accommodated in the shed... He was not provided with any bedding or covers and would place his jacket that he had worked in covered in manure over him to keep him warm.
"The toilet which Darrell used was broken and did not flush. He had to use a stick to get rid of his excreta.
"Darrell Simester regarded the defendants as his bosses. He worked (virtually) every day for 13 years.
"His working day would start at 7am and and he would finish between 9pm and 10pm. He did not receive any pay at all.
"You (the jury) will have to decide whether Mr Simester remained at the farm as a volunteer because he preferred life there, or whether he was coerced to stay while under some form of threat."
The court heard Mr Simester was brought up in the Kidderminster area - and it soon became apparent he was "timid and easily led" and had "an air of vulnerability".
Although he managed to get a C grade in O Level maths, he drifted from job to job.
In 1997, he began working as a labourer for local man called Jimmy Loveridge - a man whose name, Mr Hipkin said, carried "a certain reputation" in the Worcestershire area.
Mr Simester began living with the Loveridge family - although sleeping in a shed while they stayed in a house.
"Although he was living with them, he was still able to maintain contact with his family," Mr Hipkin said.
However, Mr Simester had a major fall out with the Loveridge's while on holiday in south Wales seaside town Porthcawl in the summer of 2000 - and attempted to walk back home to Kidderminster.
It was while making his journey on foot his paths crossed with the Doran family.
The court heard Mr Simester was picked up by the youngest defendant's brother Tom Doran, who was driving a flat bed lorry with other workers on the back of it.
Mr Hipkin said: "He was offered by Tom Doran to do some bricklaying and tarmacking for a couple of days.
"It appeared Darrell did do a couple of days work (bricklaying and tarmacking). He was promised pay, which never materialised."
Later that August, Mr Simester arrived at Cariad Farm - run by the two defendants - in Peterstone, near Marshfield.
Initially he contacted his mother Jean and father Tony and told them he was working in south Wales as he was "too scared" to return to England.
His parents were given a mobile phone number to contact him on, but that eventually rang with no answer.
Mr Simester later would call his parents between two and four times a year, but from a withheld number - and it "appeared...he was being told what to say".
When Jean and Tony asked their son for a number to contact him on, he told them he couldn't because he feared he would be killed.
And in 2008, the calls stopped altogether - prompting a missing person's investigation and appeals via the press and social media.
After numerous inquiries, information brought the family to the gates of Cariad Farm last year.
The jury was told when Mr Simester's brother walked into the farm, he saw a hunched figure shovelling manure into a wheelbarrow.
Mr Hipkin added: "Duncan approached him and eventually recognised it was his brother. He was in poor physical condition and wearing ripped clothes.
"When Darrell's father saw him, he described his son as being in a horrific state: hunched over, barely able to walk and filthy."
And on February 28, 2013, police raided the farm - arresting Doran senior and junior in the process.
The prosecution says in the 13 years Mr Simester had been there, he only ever had "two or three" breaks for Christmas lunch - and only left the farm on a handful of occasions.
It is also their case Mr Simester had been threatened to be shot and "buried out the back" with dead horses.
In its opening, the Crown also highlighted two incidents of how Mr Simester was made to feel coerced by Doran senior and junior.
One related to Mr Simester fracturing his hip after an accident involving a horse - which saw him carry on working before being taken to hospital.
Addressing the jury, Mr Hipkin said: "Would he have volunteered (to carry on working) with a broken hip.... or did they have some control over him?"
The other was after Mr Simester had accidentally set fire to a shed at Cariad Farm.
Mr Hipkin said: "Darrell Simester offered to eat less food until the damage was paid. The damage could not be deducted from his wages because there were no wages."
However, Mr Hipkin said another worker - a Polish man called Cedric - had been offered pay while at Cariad.
The jury has already been told by Judge Neil Bidder the trial of Doran junior and senior is expected to last between four and six weeks.
They have also heard Mr Simester will be giving evidence in the case next week via video link and may require regular breaks.
Daniel Doran and David Dan Doran, both of Cariad Farm, have pleaded not guilty.