Treason is the crime of attacking a state authority to which one owes allegiance. This typically includes acts such as participating in a war against one's native country, attempting to overthrow its government, spying on its military, its diplomats, or its secret services for a hostile and foreign power, or attempting to kill its head of state. A person who commits treason is known in law as a traitor.
Under the law of the United Kingdom, high treason is the crime of disloyalty to the Crown. Offences constituting high treason include plotting the murder of the sovereign; committing adultery with the sovereign's consort, with the sovereign's eldest unmarried daughter, or with the wife of the heir to the throne; levying war against the sovereign and adhering to the sovereign's enemies, giving them aid or comfort; and attempting to undermine the lawfully established line of succession. Several other crimes have historically been categorised as high treason, including counterfeiting money and being a Catholic priest.
Petty treason or petit treason was an offence under the common law of England in which a person killed or otherwise violated the authority of a social superior, other than the king. In England and Wales, petty treason ceased to be a distinct offence from murder by virtue of the Offences against the Person Act 1828. It was abolished in Ireland in 1829. It never existed in Scotland. It has also been abolished in other common-law countries.
The Treachery Act 1940 was an Act of the Parliament of the United Kingdom effective during World War II to facilitate the prosecution and execution of enemy spies, suspended afterwards, and repealed in 1968 or 1973, territory depending. The law was passed on 23 May 1940, in the month after Nazi Germany invaded France and Winston Churchill became prime minister.
Misprision of treason is an offence found in many common law jurisdictions around the world, having been inherited from English law. It is committed by someone who knows a treason is being or is about to be committed but does not report it to a proper authority.
The Treason Act 1351 is an Act of the Parliament of England which codified and curtailed the common law offence of treason. No new offences were created by the statute. It is one of the earliest English statutes still in force, although it has been very significantly amended. It was extended to Ireland in 1495 and to Scotland in 1708. The Act was passed at Westminster in the Hilary term of 1351, in the 25th year of the reign of Edward III and was entitled "A Declaration which Offences shall be adjudged Treason". It was passed to clarify precisely what was treason, as the definition under common law had been expanded rapidly by the courts until its scope was controversially wide. The Act was last used to prosecute William Joyce in 1945 for collaborating with Germany in World War II.
Misprision in English law describes certain kinds of offence. Writers on criminal law usually divide misprision into two kinds: negative and positive.
The Criminal Lunatics Act 1800 was an Act of the Parliament of Great Britain that required and established a set procedure for the indefinite detention of mentally ill offenders. It was passed through the House of Commons in direct reaction to the trial of James Hadfield, who attempted to assassinate King George III.
The Treason Act 1695 is an Act of the Parliament of England which laid down rules of evidence and procedure in high treason trials. It was passed by the English Parliament but was extended to cover Scotland in 1708 and Ireland in 1821. Some of it is still in force today.
The Treason Act 1842 is an Act of the Parliament of the United Kingdom of Great Britain and Ireland. It was passed early in the reign of Queen Victoria. The last person to be convicted under the Act was Jaswant Singh Chail, on 3 February 2023, to be sentenced on 31 March 2023. He was the first person in more than 40 years to be convicted.
The Sedition Act 1661 was an Act of the Parliament of England, although it was extended to Scotland in 1708. Passed shortly after the Restoration of Charles II, it is no longer in force, but some of its provisions continue to survive today in the Treason Act 1695 and the Treason Felony Act 1848. One clause which was included in the Treason Act 1695 was later adapted for the United States Constitution.
The Treason Act 1945 was an Act of the Parliament of the United Kingdom.
The Treason Act 1708 is an Act of the Parliament of Great Britain which harmonised the law of high treason between the former kingdoms of England and Scotland following their union as Great Britain in 1707.
The Treason Act 1554 was an Act of the Parliament of England. It is not to be confused with two other Acts about treason passed in the same year, 1 & 2 Ph & M c 9 and 11.
The Treason (Ireland) Act 1821 is an Act of the Parliament of the United Kingdom. It extended most of the English Treason Act 1695 to Ireland. Previously the 1695 Act only applied to England and Scotland.
The Treason Act 1547 was an Act of the Parliament of England. It is mainly notable for being the first instance of the rule that two witnesses are needed to prove a charge of treason, a rule which still exists today in the United States Constitution.
The Treason Act 1397 was an Act of the Parliament of England. It was supplemented by six other Acts. The seven Acts together dealt with high treason.
The Incitement to Mutiny Act 1797 was an Act passed by the Parliament of Great Britain. The Act was passed in the aftermath of the Spithead and Nore mutinies and aimed to prevent the seduction of sailors and soldiers to commit mutiny.
The Treason Outlawries (Scotland) Act 1748 was an Act of the Parliament of Great Britain which applied only to Scotland. Its long title was "An Act to ascertain and establish the Method of Proceeding to and upon Outlawries for High Treason and Misprision of High Treason, in Scotland."
The Crimes Act of 1790, formally titled An Act for the Punishment of Certain Crimes Against the United States, defined some of the first federal crimes in the United States and expanded on the criminal procedure provisions of the Judiciary Act of 1789. The Crimes Act was a "comprehensive statute defining an impressive variety of federal crimes".
