Until 1351 treason was defined by the common law. The king's judges gradually expanded the scope of treason under the pretext that any "assortment of royal power," by which was meant doing anything which only the king could legally do, was considered treason – even hunting deer in the king's forests. When a John Gerberge of Royston was convicted of treason for falsely imprisoning someone who owed him £90, the barons compelled Edward III to agree to an Act of Parliament to restrict the definition of treason to definite limits. Joseph Story wrote: "This statute has ever since remained the pole star of English jurisprudence upon this subject."
Content
The Act distinguished two varieties of treason: high treason and petty treason, the first being disloyalty to the Sovereign, and the second being disloyalty to a subject. The practical distinction was the consequence of being convicted: for a high treason, the penalty was death by hanging, drawing and quartering or drawing and burning, and the traitor's property would escheat to the Crown; in the case of a petty treason the penalty was drawing and hanging without quartering, or burning without drawing; and property escheated only to the traitor's immediate lord. The forfeiture provisions were repealed by the Forfeiture Act 1870, and the penalty was reduced to life imprisonment by the Crime and Disorder Act 1998. A person was guilty of high treason under the Act if they:
"compassed or imagined" the death of the king, his wife or his eldest son and heir ;
violated the king's companion, the king's eldest daughter if she was unmarried or the wife of the king's eldest son and heir ;
levied war against the king in his realm;
adhered to the king's enemies in his realm, giving them aid and comfort in his realm or elsewhere;
counterfeited English coinage or imported counterfeit English coinage ;
killed the Chancellor, Treasurer, one of the king's justices, a justice in eyre, an assize judge, and "all other Justices", while they are performing their offices.
The penalty for counterfeiting coins was the same as for petty treason. The offence had previously been called petty treason, before the Act elevated it to high treason. Under the Act petty treason was the murder of one's lawful superior: that is if a servant killed his master or his master's wife, a wife killed her husband or a clergyman killed his prelate. This offence was abolished in 1828. The Act originally envisaged that further forms of treason would arise that would not be covered by the Act, so it legislated for this possibility. The words from "Et si per cas" onwards have been translated as:
The Act in Scotland
Following the union of England and Scotland by the Acts of Union 1707, Scotland continued to have its own treason laws until the Treason Act 1708 abolished Scottish treason law and extended English treason law to Scotland. This Act also made it treason to counterfeit the Great Seal of Scotland, and to kill the Scottish Lords of Session and Lords of Justiciary. However while in England and Ireland forgery of the seal of Great Britain ceased to be treason under the Forgery Act 1861, this Act did not apply to Scotland. Also, forging the Scottish seal is still treason in Scotland, but has not been treason in England or Ireland since 1861. The 1351 Act still applies in Scotland today, and is a reserved matter which the Scottish Parliament has no power to modify.
Interpretation
Although the first kind of treason is described as "compassing," the offence does not consist of purely thinking. A subsequent clause which requires that an "overt act" must also be proven has been held by judges to apply to all kinds of treason. Adhering to "enemies" does not include adhering to rebels or pirates. During the trial of Roger Casement, who in 1916 was accused of collaborating with Germany during World War I, the defence argued that the Act applied only to activities carried out on British soil, while Casement had committed the acts of collaboration outside Britain. However, closer reading of the originally unpunctuated medieval document allowed for a broader interpretation, leading to the accusation by his supporters that Casement was "hanged by a comma". The court decided that a comma should be read in the text, crucially widening the sense so that "in the realm or elsewhere" meant where acts were done and not just where the "King's enemies" might be.
Repeals
The clauses about forgery and counterfeiting were repealed in 1830 and 1832. The words from "Et si per cas" onwards were repealed by the Criminal Law Act 1967 and the Criminal Law Act 1967. The Act was repealed in the Republic of Ireland on 16 May 1983, and in New Zealand on 1 January 1962.
