Capital punishment in the United Kingdom predates the Acts of Union 1707, having been used in Great Britain and Ireland from ancient times until the second half of the 20th century. The last executions in the United Kingdom were by hanging, and took place in 1964; capital punishment for murder was suspended in 1965 and finally abolished in 1969 (1973 in Northern Ireland). Although unused, the death penalty remained a legally defined punishment for certain offences such as treason until it was completely abolished in 1998; the last person to be executed for treason was William Joyce, in 1946.
In 2004, Protocol No. 13 to the European Convention on Human Rights became binding on the United Kingdom; it prohibits the restoration of the death penalty as long as the UK is a party to the convention (regardless of the UK's status in relation to the European Union).
During the reign of Henry VIII, as many as 72,000 people are estimated to have been executed. In Elizabethan England, the death penalty applied for treason, murder, manslaughter, infanticide, rape, arson, grand larceny (theft of goods worth more than a shilling), highway robbery, buggery, sodomy and heresy. Hanging was the method used for all but treason, which was punished by drawing, hanging and quartering for men, burning for women, and beheading for the nobility; and heresy, which was punished by burning. About 24% of those facing trial for such offences were actually executed. About 75% of hangings were for theft.
Sir Samuel Romilly, speaking to the House of Commons on capital punishment in 1810, declared that "[there is] no country on the face of the earth in which there [have] been so many different offences according to law to be punished with death as in England". Known as the "Bloody Code", at its height the criminal law included some 220 crimes punishable by death, including "being in the company of Gypsies for one month", "strong evidence of malice in a child aged 7–14 years of age" and "blacking the face or using a disguise whilst committing a crime". Many of these offences had been introduced by the Whig oligarchy to protect the property of the wealthy classes that emerged during the first half of the 18th century, a notable example being the Black Act 1723, which created 50 capital offences for various acts of theft and poaching. Crimes eligible for the death penalty included shoplifting and stealing sheep, cattle, and horses, and before abolition of the death penalty for theft in 1832, "English law was notorious for prescribing the death penalty for a vast range of offences as slight as the theft of goods valued at twelve pence."
Whilst executions for murder, burglary and robbery were common, the death sentences for minor offenders were often not carried out. A sentence of death could be commuted or respited (permanently postponed) for reasons such as benefit of clergy, official pardons, pregnancy of the offender or performance of military or naval duty. The final decision to grant an official full or partial (conditional) pardon to commute the sentence rested with the 'hanging cabinet' (or Grand Cabinet), a senior group of government ministers under the authority of the monarch and directed by the Home Secretary or Prime Minister. The group would assemble in the presence of the reigning monarch and review a list from the Recorder of London of 'Capital Convicts'.
Between 1770 and 1830, an estimated 35,000 death sentences were handed down in England and Wales, of which 7,000 executions were carried out.
In 1808, the lawyer Samuel Romilly KC successfully had the law changed to remove the death penalty for pickpockets and lesser offenders, starting a process of reform that continued over the next 50 years. The death penalty was mandatory (although it was frequently commuted by the government) until the Judgement of Death Act 1823 gave judges the official power to commute the death penalty except for treason and murder. The Punishment of Death, etc. Act 1832 reduced the number of capital crimes by two-thirds. In 1832, the death penalty was abolished for theft, counterfeiting, and forgery except for the forgery of wills and certain powers of attorney. The meeting of the 'hanging cabinet' (or grand cabinet) which decided on the application of mercy was criticised for its irregular meeting and lack of formal procedure. Under George IV, cartoons satirised how the King favoured decisions over his personal wardrobe ahead of decisions on the life and death of prisoners.
Gibbeting was abolished in 1832 and hanging in chains was abolished in 1834. In 1837, the death penalty for forging wills and powers of attorney was abolished. The death penalty for rape and some other offences was abolished by the Substitution of Punishments of Death Act in 1841. In 1861, several acts of Parliament (24 & 25 Vict. c. 94 to c. 100) further reduced the number of civilian capital crimes in England and Wales to five: murder, treason, espionage, arson in royal dockyards, and piracy with violence; there were other offences under military law. The 1866 report of the Royal Commission on Capital Punishment noted further obsolete capital offences in Scots law which had not yet been formally repealed. The death penalty remained mandatory for treason and murder unless commuted by the monarch.
The 1866 royal commissioners concluded (with dissenters) that there was not a case for abolition but recommended an end to public executions. This proposal was included in the Capital Punishment Amendment Act 1868. From that date executions in Great Britain were carried out only in prisons. The punishment of beheading and quartering those executed for treason was abolished in 1870. The last application of that punishment had been in 1820 and the last sentence to the punishment had been in 1839.
The Criminal Procedure (Scotland) Act 1887 abolished the death penalty in Scots law for crimes other than murder, "treason or rebellion against the Sovereign", and (in theory but not in practice) certain types of attempted murder.
Relevant offences, which were obsolete or for which lesser punishments had long applied in practice, included
breaking into houses or ships;
certain classes of malicious mischief;
returning to Scotland after banishment for performing a marriage without banns;
In 1902, the tradition of raising a black flag over the prison where a death sentence was carried out, was replaced with a notice published on the prison gates due to poor behaviour from members of the public. In 1908, the Children Act 1908 banned the execution of juveniles under the age of 16. In 1922, a new offence of infanticide was introduced to replace the charge of murder for mothers killing their children in the first year of life. In 1930, a parliamentary select committee recommended that capital punishment be suspended for a trial period of five years, but no action was taken. From 1931, pregnant women could no longer be hanged (following the birth of their child) although, in practice, since the 18th century their sentences had always been commuted.
In 1933, the minimum age for capital punishment was raised to 18 under the Children and Young Persons Act 1933. The last known execution by the civilian courts of a person under 18 was that of Charles Dobell, 17, hanged at Maidstone together with his accomplice William Gower, 18, in January 1889. Harold Wilkins, at 16 years old, was the last juvenile sentenced to the death penalty in the United Kingdom, in 1932 for a sexually related murder, but he was reprieved due to age.
In 1938, the issue of the abolition of capital punishment was brought before parliament. A clause within the Criminal Justice Bill called for an experimental five-year suspension of the death penalty. When war broke out in 1939 the bill was postponed. It was revived after the war in 1948 and was adopted by a majority in the House of Commons (245 to 222). In the House of Lords, the abolition clause was defeated but the remainder of the bill was passed as the Criminal Justice Act 1948. Popular support for abolition was absent and the government decided that it would be inappropriate for it to assert its supremacy by invoking the Parliament Act 1911 over such an unpopular issue.