HM Prison Wandsworth, Wandsworth Reform Prison, is a Category B men's prison at Wandsworth in the London Borough of Wandsworth, South West London, England. It is operated by Her Majesty's Prison Service and is the largest prison in the United Kingdom.HistoryThe prison was built in 1851, when it was known as Surrey House of Correction. It was designed according to the humane separate system principle: a number of corridors radiate from a central control point with each prisoner having toilet facilities. The toilets were subsequently removed to increase prison capacity and the prisoners had to engage in the humiliating process of "slopping out", until 1996.In 1930, inmate James Edward Spiers, serving a 10-year sentence for armed robbery, committed suicide in front of a group of Justices of the Peace who were there to witness his receiving 15 lashes, then a form of judicial corporal punishment.In 1951, Wandsworth was the holding prison for a national stock of the birch and the cat o' nine tails, implements for corporal punishment inflicted as a disciplinary penalty under the prison rules. An example of a flogging with the "cat" carried out in Wandsworth Prison itself was reported in July 1954.