In Roman law the offences originally falling under the head of treason were almost exclusively those committed in military service, such as in England would be dealt with under the Army Act. The very name perduellio, the name of the crime in the older Roman law, is a proof of this. Perduelles were, strictly, public enemies who bore arms against the state; and traitors were regarded as having no more rights than public enemies. The Twelve Tables made it punishable with death to communicate with the enemy or to betray a citizen to the enemy. Other kinds of perduellio were punished by interdiction of fire and water. The crime was tried before a special tribunal, the duumviri perduellionis, perhaps the earliest permanent criminal court existing at Rome. At a later period the name of perduellio gave place to that of laesa majestas, deminuta or minuta majestas, or simply majestas. The lex Julia majestatis, to which the date of 48 b.c. has been conjecturally assigned, continued to be the basis of the Roman law of treason until the latest period of the empire. The original text of the law appears to have still dealt with what were chiefly military offences, such as sending letters or messages to the enemy, giving up a standard or fortress, and desertion. With the empire the law of majestas received an enormous development, mainly in the reign of Tiberius, and led to the rise of a class of professional informers, called delatores. The conception of the emperor as divine had much to do with this. It became a maxim that treason was next to sacrilege in gravity. The law as it existed in the time of Justinian is contained chiefly in the titles of the Digest and Code “Ad legem Juliam majestatis.” The definition given in the Digest (taken from Ulpian) is this: “majestatis crimen illud est quod adversus populum Romanun vel adversus securitatem ejus committitur.” Of treasons other than military offences, some of the more noticeable were the raising of an army or levying war without the command of the emperor, the questioning of the emperor’s choice of a successor, the murder of (or conspiracy to murder) hostages or certain magistrates of high rank, the occupation of public places, the meeting within the city of persons hostile to the state with weapons or stones, incitement to sedition or administration of unlawful oaths, release of prisoners justly confined, falsification of public documents, and failure of a provincial governor to quit his province at the expiration of his office or to deliver his army to his successor. The intention (voluntas) was punishable as much as an overt act (effectus). The reported opinions as to what was not treason show the lengths to which the theory of treason must have been carried by at least some person in authority. It was not treason to repair a statue of the emperor which had decayed from age, to hit such a statue with a stone thrown by chance, to melt down such a statue if unconsecrated, to use mere verbal insults against the emperor, to fail in keeping an oath sworn by the emperor, or to decide a case contrary to an imperial constitution. Treason was one of the “publica judicia,” i.e., one of those crimes in which any citizen was entitled to prosecute. The law went further than this, and deprived the accused in a charge of treason of his ordinary remedy for malicious prosecution. It also took from him the privilege (which those accused of other crimes generally possessed) from accusation by women or infamous persons, from liability to be put to the torture, and from having his slaves tortured against him (see Torture). The punishment from the time of Tiberius was death (usually by beheading) and confiscation of property, coupled with complete civil disability. A traitor could not make a will or a gift or emancipate a slave. Even the death of the accused, if guilty of treason of the gravest kind, such as levying war against the state, did not extinguish the charge, but the memory of the deceased became infamous, and his property was forfeited as though he had been convicted in his lifetime.

The law of England corresponds to a considerable extent with Roman law; in fact, treason is made by Blackstone the equivalent of the crimen laesae majestatis. The history of the crime in the two systems agrees in this that in both the law was settled by legislation at a comparatively early period, and subsequently developed by judicial construction. In both, too, there were exceptional features distinguishing this crime from other offences. For instance, at common law treason was not bailable (except by the Queen’s Bench) or clergyable, could not be cleared by sanctuary, and did not admit of accessories, for all were principals, nor could a married woman plead coercion by her husband. To stand mute and refuse to plead did not save the lands of the accused, as it did in felony, so that the “peine forte et dure” (see Torture) was unnecessary in treason. These severities were due to the conception of treason as a breach of the oath of allegiance. Other differences introduced by statute will be mentioned later. In some cases a statute simply affirmed the common law, as did the Statute of Treasons to a great extent, and as did 26 Hen. VIII. c. 13, depriving those accused of treason of the benefit of sanctuary. How far the Roman law was consciously imitated in England it is impossible to determine. It was certainly not adopted to its full extent, for many acts were majestas which were never treason, even in the most despotic periods. Treason was the subject of legislation in many of the pre-Conquest codes. The laws of Alfred and Aethelred punished with death any one plotting against the life of the king. Soon after the Conquest the Leges Henrici Primi put any one slaying the king’s messenger in the king’s mercy. The crime was shortly defined by Glanvill and at greater length by Bracton, who follows Roman law closely. He includes under treason sedition and coining. Treason seems to have rested chiefly, if not wholly, upon common law until the year 1352, when the famous Statute of Treasons (25 Edw. III. st. 5, c. 2) was passed. The statute appears to have arisen from a petition of the Commons in 1348, praying for a definition of the offence of accroaching royal power, a charge on which several persons—notably Gaveston and the Despencers—had suffered. The offences made treason by the statute are these:—(1) to compass or imagine the death of the king, the queen, or their eldest son and heir; (2) to violate the king’s companion, or his eldest daughter unmarried, or the wife of his eldest son and heir; (3) to levy war against the king in his realm, or be adherent to the king’s enemies in his realm, giving them aid and comfort in the realm or elsewhere; (4) to counterfeit the king’s great or privy seal or his money; (5) to bring false money into the realm, counterfeit to the money of England, as the money called Lushburgh, knowing the money to be false; (6) to slay the chancellor, treasurer, or the king’s justices of the one bench or the other, justices in eyre, or justices of assize, and all other justices assigned to hear and determine, being in their places doing their offices. The statute further defined petty treason to be the slaying of a master by his servant, a husband by his wife, or a prelate by a man secular or religious owing him allegiance. In all cases of treason not specified in the statute the justices before whom the case came were to tarry without going to judgment until the cause had been showed and declared before the king and his parliament whether it ought to be judged treason or felony. The statute, so far as it defines the offence, is still law, except the clauses as to counterfeiting the seal, coining, and petit treason, repealed respectively, after a considerable amount of intermediate modification by statute, by 11 Geo. IV. and 1 Will. IV. c. 66, 2 and 3 Will. IV. c. 34, 30 Geo. III. c. 48, and 9 Geo. IV. c. 31. Petit treason is now treated as murder, 24 and 25 Vict. c. 100. From the time of the passing of the Statute of Treasons the limits of treason were continually being extended for a time, and again reduced to the bounds fixed by the statute. It protected only the king’s life, and its insufficiency was supplemented in periods of danger by legislation, often of a temporary nature. Under Richard II. and Henry VIII. many new offences were made treason, but the Acts creating these new treasons were repealed at the earliest opportunity by the parliaments of their successors, and the Statute of Treasons was made the final standard by 1 Mary, sess. 1, c. 1. The reign most prolific in statutory additions to the law of treason was undoubtedly that of Henry VIII. Legislation in this reign was little more than a register of the fluctuating opinions of the monarch. Thus, by 25 Hen. VIII. c. 22 it was treason not to believe Mary illegitimate and Elizabeth legitimate; by 28 Hen. VIII. c. 7 it was treason to believe either legitimate; by 35 Hen. VIII. c. 1 it was treason not to believe both legitimate. An interesting act of this reign, 37 Hen. VIII. c. 10, shows that a class of men like the Roman delatores must have been called into existence by all the new legislation. The Act constituted it felony to make anonymous charges of treason without daring to appear in support of them before the king or council. Out of the mass of Henry VIII.’s Acts, only two are still law,—28 Hen. VIII. c. 15 and 35 Hen. VIII. c. 2, giving power to try treasons committed within the jurisdiction of the admiralty and out of the realm. Many other instances of offences of a temporary kind made treason at different times occur among the statutes, especially in those levelled at the papal jurisdiction by the parliaments of Elizabeth. A few of the more interesting of other kinds may be briefly noticed. It was treason by 21 Ric. II. c. 4 to attempt to appeal or annul judgments made by parliament against certain traitors; by 2 Hen. V. st. 1, c. 6, and 29 Hen. VI. c. 2 to break a truce or safe-conduct; by 5 and 6 Edward VI. c. 11 to hold castles, fortresses, or munitions of war against the king; by 17 Car. II. c. 5 to adhere to the United Provinces; by 9 Will. III. c. 1 to return without licence if an adherent of the Pretender; by 12 and 13 Will. III. c. 3 to correspond with the Pretender; and by 57 Geo. III. c. 6 to compass or imagine the death of the prince regent. In addition to these, many Acts of attainder were passed at different times. One of the most severe was that against Catherine Howard, 33 Hen. VIII. c. 21, which went as far as to make it treasonable for any queen to conceal her antenuptial incontinence. Other Acts were those against Archbishop Scrope, Owen Glendower, Jack Cade, Lord Seymour, Sir John Fenwick, James Stuart, and Bishop Atterbury. In one case, that of Cromwell, Ireton, and Bradshaw, an Act of attainder was passed after the death of those guilty of the treason, 12 Car. II. c. 30. At times

Acts of indemnity were passed to relieve those who had taken part in the suppression of rebellion from any possible liability for illegal proceedings. Three such Acts were passed in the reign of William III.

The Statute of Treasons, as interpreted by the judges, is still the standard by which an act is determined to be treason or not. The judicial interpretation has been sometimes strained to meet cases scarcely within the contemplation of the framers of the statute: e.g., it became established doctrine that a conspiracy to levy war against the king’s person or to imprison or depose him might be given in evidence as an overt act of compassing his death, and that spoken words, though they could not in themselves amount to treason, might constitute an overt act, and so be evidence. Besides decisions on particular cases, the judges at different times came to general resolutions which had an appreciable effect on the law. The principal resolutions were those of 1397 (confirmed by 21 Ric. II. c. 12), of 1557, and those agreed to in the case of the regicides at the Restoration and reported by Sir John Kelyng. A remarkable resolution in favorem rei among the latter was that a prisoner ought not to be ironed during trial. The result of judicial decisions on the Statute of Treasons was summed up in Acts passed in 1786, made permanent in 1817 and in 1848 (57 Geo. III. c. 6 and 11 Vict. c. 12, the latter often called the Treason Felony Act). The effect of this legislation, according to Mr Justice Stephen, is that such of the judicial constructions as extend the imagining of the king’s death to imagining his death, destruction, or any bodily harm tending to death or destruction, maim or wounding, imprisonment or restraint, have been adopted, while such of the constructions as make the imagining of his deposition conspiring to levy war against him, and instigating foreigners to invade the realm, have not been abolished, but are left to rest on the authority of decided cases. The present state of the law has been incorporated by skilled lawyers in the draft criminal code, which will no doubt become an Act when parliament has leisure to devote to matters of this kind. The code draws a distinction between treason and treasonable crimes, the former including such acts (omitting those that are obviously obsolete) as by the Statute of Treasons and subsequent legislation are regarded as treason proper, the latter including the crimes contained in the Act of 1848. In the words of the code (§ 76) “treason is (a ) the act of killing Her Majesty, or doing her any bodily harm tending to death or destruction, maim or wounding, and the act of imprisoning or restraining her; or (b) the forming and manifesting by an overt act an intention to kill Her Majesty, or to do her any bodily harm tending to death or destruction, maim or wounding, or to imprison or to restrain her; or (c) the act of killing the eldest son and heir-apparent of Her Majesty, or the queen consort of any king of the United Kingdom of Great Britain and Ireland; or (d ) the forming and manifesting by an overt act an intention to kill the eldest son and heir-apparent of Her Majesty, or the queen consort of any king of the United Kingdom of Great Britain and Ireland; or (e ) conspiring with any person to kill Her Majesty, or to do her any bodily harm tending to death or destruction, maim or wounding, or conspiring with any person to imprison or restrain her; or (f ) levying war against Her Majesty either with intent to depose Her Majesty from the style, honour, and royal name of the imperial crown of the United Kingdom of Great Britain and Ireland or of any other of Her Majesty’s dominions or countries; or in order by force or constraint to compel Her Majesty to change her measures or counsels, or in order to intimidate or overawe both Houses or either House of Parliament; or (g ) conspiring to levy war against Her Majesty with any such intent or for any such purpose as aforesaid; or (A) instigating any foreigner with force to invade this realm or any other of the dominions of Her Majesty; or (i) assisting any public enemy at war with Her Majesty in such war by any means whatsoever; or (y) violating, whether with her consent or not, a queen consort, or the wife of the eldest son and heir-apparent for the time being of the king or queen regnant.” There are a few other Acts still in force besides those of 1817 and 1848 which have dealt with substantive law. By 11 Henry VII. c. 1 obedience to the de facto sovereign for the time being is not treason. By 1 Anne st. 2, c. 21, it is treason to endeavour to hinder the next successor to the crown from succeeding, and by 6 Anne c. 41 it is treason to maliciously, advisedly, and directly by writing or printing maintain and affirm that any person has a right to the crown otherwise than according to the Acts of Settlement and Union, or that the crown and parliament cannot pass statutes for the limitation of the succession to the crown.

The Acts dealing with procedure and punishment are more numerous, and are characterized by a slowly increasing favour shown to the accused,—in fact, considerably greater than in felony, for counsel were not allowed to prisoners in charges of felony until 1836, and such prisoners are still not entitled to a copy of the indictment or the names of the witnesses or jury. With respect to the mode of trial, the effect of common law and legislation is that there are now four varieties,— Impeachment ( q.v.) trial of a peer by the peers, court martial, and trial by a judge of the High Court of Justice and a jury. The offence cannot be tried at quarter sessions. Trial by battle in cases of treason ceased in the 14th century, as far as regards appeals in the common law courts or in parliament, by the effect of several statutes passed between 1332 and 1399. Appeals of treason were finally abolished in 1819 (see Appeal). In the court of the lord high constable an award of battle occurred as lately as 1631 in the case of Lord Rea. Traitors in the reign of Edward 1V., and perhaps later, were at times tried by martial law. The issue of commissions of martial law in time of peace was declared illegal by the Petition of Right in 1628. The prerogative of the crown to try traitors by martial law in time of open rebellion still exists, and is recognized by statute. In two Acts, for instance, dealing with Ireland, 43 Geo. III. c. 117 and 3 and 4 Will. IV. c. 4, it was provided that nothing in the Acts was to take away the undoubted prerogative of the crown for the public safety to resort to the exercise of martial law against open enemies and traitors. A peer is tried before the House of Lords, or the court of the lord high steward if the trial be during the recess of parliament. Procedure in such trials is regulated by 7 and 8 Will. III. c. 3, and other Acts. The last trial of a peer for treason was that of Lord Lovat in 1746-47. Persons subject to naval or military law are triable by court martial in certain cases under the powers given by the Naval Discipline Act, 1866, and the Army Act, 1881. The trial of treason committed out of the realm is regulated by 35 Hen. VIII. c. 2, 5 and...