The site of Hadleigh Farm was formally acquired by The Salvation Army on 2 May 1891. The establishment of the Land and Industrial Colony was part of The Salvation Army's Darkest England Scheme to raise 'the submerged tenth' of society. Integral to this was the movement of Britain's unemployed from city "slums" "back to the land". This was originally envisaged as a three step process: the Hadleigh Colony would take in destitute but able bodied men who had been temporarily 'rehabilitated' in the Salvation Army's City Colony in London; at Hadleigh these men would undergo agricultural training and moral rehabilitation in order to become 'capable, industrious citizens'; some men would remain in England but most would emigrate to British colonies overseas, notably Canada, Australia and New Zealand.
The Colony was run by a Governor appointed by the General. Some men made personal applications to Hadleigh; others were sent from Boards of Guardians. All men worked in exchange for basic maintenance and it was intended that the Colony be self supporting through farm produce. By 1914 over 3,000 acres of the site were under cultivation. At this time the Colony operated a Farm, Dairy, Brickfields, Stores, Works and Market Garden. Some produce was sold locally in Southend; others, such as bricks, were traded between Essex and London. The Colony was known for its pedigree rare breeds and in particular pigs.
Religious and social institutions were an important part of the Colony. The Colony had its own Citadel and operated with the belief that 'the best and only lever to use in raising the submerged is Salvation'. Upon admittance men agreed to total abstinence from strong drink. A separate Inebriate's Home (Victoria House) was opened on site in 1901.
The first Colonists to emigrate from Hadleigh left in 1901. However by 1910 it was evident that sending migrants to land settlements overseas was decreasingly viable. The Colony moved away from the rehabilitation of older men towards the training of younger men who could obtain paid jobs overseas, for instance as farm hands. Froom 1923 until 1939 thousands passed through the Colony as part of the Boys' Training and Migration Scheme; they were drawn from various parts of Britain at the discretion of The Salvation Army's Emigration Department.
During the second world war some of the site was requisitioned by the Government's War Office. From 1945 the number of Colonists and output of work steadily decreased. The Salvation Army started accepting applicants from probation services but even so numbers were few and the nature of the farm work was considered inappropriate for many men. Throughout the 1950s-1980s the Colony faced financial difficulties in maintaining the site.
In 1990 the site of Hadleigh Farm Colony, as it was then called, became an Employment Training Centre specialising in programmes to assist people with 'special training needs'; at present (August 2013) this work continues under the name Hadleigh Farm. The site is also used for commercial farming; has a Rare Breeds Centre; and houses Hadleigh Castle, an English Heritage site.