Two inmates who took part in a prison riot sparked by a ban on smoking and short-staffing have been found guilty of prison mutiny.
Luke Needham, 30, and Deno Harrison, 23, were convicted at Winchester Crown Court for their part in the disturbance at HMP Erlestoke in Wiltshire on June 11 2016.
A third prisoner, Andrew Alford, 41, was acquitted by the jury.
Rob Welling, prosecuting, told the trial that tensions rose during the June weekend after prisoners were ordered to remain in their cells for the day because of a shortage of prison staff.
He said the situation had been worsened by two officers being required to escort a prisoner to hospital as well as raised tensions from a previous disturbance earlier that week.
He explained that the prison was category C, meaning that it houses inmates of various levels of offending but who were not considered likely to attempt to escape.
Mr Welling said problems began after a national prison smoking ban was being trialled at the site.
He said: "As you can imagine it caused tensions to rise among prisoners as it was, frankly, a very unpopular move.
"And like other public bodies, the prison was short-staffed and if they couldn't safely supervise prisoners they would instruct a lockdown as happened on this occasion."
He added: "Tension was heavy and the atmosphere was very unpleasant and threatening."
He said the "slow process" of delivering meals to the cells by the short-handed staff prompted the unrest during the lockdown on the Saturday morning.
Mr Welling said Needham then set fire to his cell and flooded it before kicking open his wooden cell door and helping other prisoners to escape their rooms.
He said Needham and Harrison managed to get on to the rooftop and refused to come down until after midnight when a trained negotiator and backup officers had arrived at the prison.
He said that after calm was restored on the Sunday a total of 120 prisoners had to be rehoused at prisons around the country and damage costing "many thousands of pounds" had been caused to
the cells as well as to windows and CCTV systems.
Mr Welling said Needham refused to comment when questioned by police while Harrison said he had smoked the drug "Spice" and could not remember his actions.
Alford had been accused of breaking out of his cell on another wing but he later told police that his "mental health was bad that day".
Needham and Harrison, along with Ben Sharratt, 26, who previously pleaded guilty to the same offence, will be sentenced on March 16.