Treason may be defined in general terms as an attempt to overturn the government established by law. In early times it was regarded entirely as an offence against the monarch in whom that government was personified, and this view is still apparent in the present state of the law. The foundation of the English legislation on the subject is the Statute of Treasons (25 Ed. III. sect. 5), 1352. Previous to that the law was vague. Murder, highway robbery, piracy, even charging the king wrongfully, were sometimes punished as treason. What was termed 'accoaching'—i.e. assuming or trespassing on royal power—also fell under this designation. The Statute of Treasons was passed to declare the law on the subject. It enumerated various acts which constitute the crime. These were compassing the king or queen's death, or that of the heir; seducing his wife or eldest daughter, or the wife of his heir; levying war against the king, or assisting his enemies; killing the judges whilst in the execution of their duty. A later age found this, as other mediæval acts, alike redundant and defective. There has never been any prosecution under some of its provisions, and many varieties of attacks on the state or its ruler did not come within its plain meaning. The judges gave a forced construction to the clauses, and thus widened their application; yet there was much fresh legislation. Under Henry VII. (1494) it was enacted that obedience to the king de facto but not de jure was not treason. Under Henry VIII. there were nine acts passed creating fresh treasons, but these were all swept away in the first year of his successor. Again, acts on the subject were passed under the Stuarts, and were in turn superseded by laws passed after the Revolution.
The provisions of the Statute of Treasons above mentioned still remain in force. It is to be noted that the offence consists in imagining the sovereign's death, and that it is proved by such overt acts as display the intention. As to levying war, this includes an attempt by force 'to compel the sovereign to change his measures or counsels, or to intimidate or overawe both Houses or either House of Parliament,' or an attempt 'by an insurrection of any kind to effect any general public object,' as, for instance, to pull down dissenting meeting-houses generally. Although the speaking of words expressing and imagining the king's death is not of itself an overt act, yet if written or accompanied by words of advice or command they constitute such an act. In treason every accessory is a principal traitor.
An act of 1848 provides a maximum punishment of penal servitude for life for those who shall be guilty of the treason felony of attempting to deprive the Queen of any of her dominions, or of making war against her. A previous act (1842) punishes by imprisonment and whipping those who shall strike or threaten the Queen. Insulting the sovereign, attempting to seduce soldiers, illegal drilling, and assisting at royal marriages to which the sovereign has not given consent are offences akin to treason. Offences against the state are called high-treason. It is distinguished from petty-treason—the murder of a husband by his wife, a master by his servant, or an ecclesiastical superior by his inferior. These crimes are now treated as other murders; and the term petty-treason was abolished in 1828. Formerly the trials for these were similar in many respects to those for the graver offence. Misprision of treason is knowledge of the principal crime and concealment thereof. It is still punishable with forfeiture of goods as well as imprisonment for life. Sediton (q.v.) is cognate to treason; Coining (q.v.) used to be dealt with as treason. See also PRÆMUNIRE.
At common law but one witness was required, but by an act of Edward VI. two witnesses were necessary, though they may speak to different overt acts of the same kind. This was often evaded in later practice before the Revolution. At the trial of Algernon Sidney (q.v.) in 1683 the want of one witness was supplied by a pamphlet found in the prisoner's study, affirming that the king was subject to parliament, and that 'we may therefore change or take away kings.' The accused must, before his trial, be furnished with a copy of the indictment, a list of witnesses and jury. For two centuries he has been allowed the assistance of counsel, a privilege not granted to those accused of felony till very recent times. Also the trial must take place within three years of the commission of the alleged offence, unless it be the attempted assassination of the king, in which case the prisoner shall be tried in the same manner as if charged with murder.
The punishment for high-treason has always been death. In its old savage form, first inflicted in 1284 on the Welsh prince David, and on Sir William Wallace a few years later, and in force till 1870, the sentence provided that the criminal should be drawn on a hurdle to the place of execution, be hanged but not till he is dead, be cut down and have his entrails torn out and burned before his eyes, and then be beheaded and quartered, his remains to be disposed of as the king should think fit (see DRAWING AND QUARTERING). That sentence was last passed (though not carried out) in 1867 on the Fenians Burke and O'Brien. Women were burned alive, though the sentence might be commuted by the king to beheading, as in the case of Lady Alicia Lisle (q.v.). The punishment is now execution by hanging. The Act of 1870 prevented forfeiture of property on conviction for treason; but it is thought the Act of 1668, abolishing public executions, does not apply to those convicted of this crime. See Stephen's Digest, p. 45.
Law of Treason in Scotland.—After the Union (1707) an act (7 Anne, c. 21) was passed making the Scots law of treason the same as the English. Thus the prosecution is not at the instance of the Lord Advocate but on the presentment of a grand jury, and there is a petty jury of twelve who determine the guilt or innocence of the prisoner. Trial in absence or after death was also abolished. The traitor's property is still forfeited, as the Act of 1870 does not apply to Scotland.
In the United States, where the people as a community, and not any one individual, is sovereign, treason is necessarily confined to levying war against the state, or adhering to and giving aid and comfort to its enemies. It implies the assembling of a body of men for the purpose of overturning or resisting the government by force; but an assembly for deliberative purposes alone does not fall under the head of treason, since the law distinguishes between deliberation and—what is a distinct step beyond it—any act of war, even though the latter be the direct outcome of the former.
See Chitty, On the Criminal Law; Stephen, Digest and History of the Criminal Law; State Trials; Macdonald, Treatise on the Criminal Law of Scotland.