Between 1830 and 1914 there were three major changes in the ways convicted offenders were treated:
- There was a shift from death or transportation as the major punishment for felonies to imprisonment in custom-built prisons.
- There was a shift, admittedly less marked, from the personnel of the courts making all key decisions about the offender to the experts in the new prison system making some of these decisions.
- Once it was agreed that most offenders should be sent to prison, the crucial arguments centred on to what extent prisons were places of punishment or reformation.
The traditional view of changes in punishment accepts that the 'Bloody Code' was arbitrary and savage and that the reformers' stance was moral unassailable. Penal reform began with the abolition of capital statutes urged by Romilly and Mackintosh and largely carried out by Sir Robert Peel and Lord John Russell when Home Secretaries in the 1820s and 1830s. It gathered pace as the government took an increasing role in the organisation and supervision of prisons with the opening of Millbank in 1816 and Pentonville in 1842, with the creation of the prison Inspectorate in 1835 and the centralisation of the whole system under the Home Office in 1877. Revisionist historians accept the savagery of the 'Bloody Code' but have been more subtle in assessing its arbitrariness and see the emergence of the new prison system as a further institutional solution to the need for social control and discipline like the workhouse established under the new Poor Law. In many respects the arguments of traditionalists and revisionists are the mirror image of each other. In the traditional Whig view the humanitarian and progressive nature of penal reform fits with the humanitarian and progressive requirements of the liberal democratic society that emerged in the early nineteenth century. In the revisionist account there is a fit between the new system of prison and punishment and the control requirements of the developing capitalist system.
 The most vivid revisionist study on prisons is Michael Ignatieff A Just Measure of Pain: the penitentiary in the Industrial Revolution 1750-1850, Macmillan, 1978. J.A.Sharpe Judicial Punishment in England, Faber, 1990 covers a broader span of time. V.A.C. Gatrell The Hanging Tree. Execution and the English People 1770-1868, OUP, 1994 is a major study of changing sensibilities and debunks many myths about execution.