Formerly named the Penitentiary, Millbank was a gloomy forbidding place built on the bank of the River Thames where the Tate Gallery now stands.
The prison building was based on the work of Jeremy Bentham in 1791. This was a round prison with cells on the circumference facing a core at the centre where guards would sit and view all cells, thereby creating the appearance of constant surveillance.
Bentham had been unable to secure funding for the prison, and the government took over the contract, completing it in 1821.
Portland Gaol was a penal service institution on the south coast, established in 1848 to house one thousand, five hundred convicts generally serving the second stage of their sentence on public works, having spent the first stage at a prison specially modelled for solitary confinement.
Portland Island on which the gaol was built was not an island at all, but a peninsula joined to the mainland by a mound of treacherous shingle. It gained its term from the fact that travel to the island was by ferry from Weymouth across the stretch of water known as Portland Roads.
The majority of the prisoners were employed in quarrying stone for the new breakwater below.
This modified version was shaped like a six pointed star, the external walls built like a fortress enclosing more than sixteen acres of low, marshy land, seven of which was covered by the prison building itself. It was the largest prison in England, with three miles of labyrinthine passages and winding staircases.
By September of that year, part of the prison had been made ready to house warders and military guards and on 1st November these arrived, followed by a small consignment of convicts.
The latter were detailed to repair and fit the remainder of the war prisons and by December sufficient work had been done for the permanent occupation of convicts. Dartmoor Prison was expected to be able to hold one thousand, three hundred convicts.
The original prison at Princetown on Dartmoor was built to house prisoners of war, but following the departure of French and American prisoners in the early nineteenth century, it was closed and had fallen into disrepair. However, when available prisons became too overcrowded and there were problems with the transportation of convicts, after several feasibility studies, it was finally agreed in 1850 to re-open Dartmoor Prison.