The Slow Evolution Of British Treason Laws

In May 1977, the Law Commission published Working Paper No. 72, examining one of England's most ancient yet problematic areas of criminal law: treason, sedition, and related offences. This consultation document represents a fascinating snapshot of legal thinking at a crossroads, proposing wholesale modernisation of medieval statutes. The subsequent forty-five years, however, tell a story of remarkable legislative inertia punctuated by modest reforms.

The full document can be downloaded and viewed here:

The Historical Context

The paper's central concern was the Treason Act 1351, a statute over 600 years old written in archaic French-influenced legal language. Despite numerous amendments and interpretations, this mediaeval law remained the foundation of English treason law. The Commission noted the unsatisfactory situation whereby "the most serious of all criminal offences should turn on the construction of language some 600 years old, which is both obscure and difficult."

The 1351 Act defined treason through several categories: compassing the death of the Sovereign, violating certain royal ladies, levying war against the King, adhering to the King's enemies, and killing high officials whilst performing their duties. Subsequent legislation in 1795 and 1848 had created overlapping offences of treason felony, adding further complexity without clarifying the underlying principles.

The Core Proposals for Treason Reform

The Commission's provisional recommendations represented a wholesale restructuring of treason law, moving from personal allegiance to the monarch towards protection of the constitutional state.

Wartime Treason

The most pressing reform concerned treason during armed conflict. The Commission proposed abolishing all existing treason statutes and replacing them with a single, clearly-defined wartime offence. This would apply only during an actual state of war (in the strict international law sense) and would penalise any conduct likely to help an enemy country or hinder prosecution of the war by the United Kingdom.

Crucially, the proposal moved away from concepts of personal allegiance. Rather than requiring breach of a feudal duty to the monarch, the offence would focus on objective conduct endangering national security. The defendant would need to intend to help an enemy, or have no substantial doubt this would result from their conduct, and must act without lawful excuse.

The Commission carefully delineated who would be subject to this offence: all British subjects who were citizens of the United Kingdom and Colonies anywhere in the world, and any person (including enemy aliens) voluntarily present in the United Kingdom. This represented a significant clarification over the confused common law rules on allegiance, particularly following the controversial Joyce case of 1946.

The Treason Act 1351 remains on the statute books in 2024, essentially unchanged from its mediaeval form. The proposals for a modern wartime treason offence were never implemented. The most significant change came much later through the Crime and Disorder Act 1998, which finally abolished the death penalty for treason (replacing it with life imprisonment), but this addressed punishment rather than the substantive definition of the offence. The archaic language, the feudal concepts of allegiance, and the judicially-created extensions remain the law today.

Peacetime Offences Against the State

More contentious was whether any treason-type offence should exist during peacetime. The Commission acknowledged the practical argument against retention: the criminal law already provided adequate means to prosecute those attempting violent overthrow of government through ordinary offences like murder, riot, conspiracy, and criminal damage. Statistics showed treason charges had become virtually obsolete, with only one peacetime treason felony charge between 1956 and 1974 (subsequently dropped).

However, the Commission provisionally recommended retaining a specific peacetime offence penalising conduct aimed at overthrowing or supplanting constitutional government by force. The argument rested on principle rather than practicality: the State should treat as the most reprehensible crime in its criminal code any attempt to destroy the constitutional system through illegal means, regardless of whether other offences might technically cover the same conduct.

This represented a significant shift from treason as breach of personal loyalty towards treason as an offence against constitutional order. The Commission was essentially proposing to enshrine protection of democratic governance as the paramount concern of the criminal law.

The Treason Felony Act 1848 remains in force, with its Victorian language intact. No modern peacetime offence of attacking constitutional order was created. However, Parliament did develop alternative approaches to political violence through terrorism legislation, beginning with the Prevention of Terrorism (Temporary Provisions) Act 1974 (initially focused on Northern Ireland) and culminating in the comprehensive Terrorism Act 2000 and subsequent amendments. These created a parallel framework for prosecuting political violence without invoking treason, effectively achieving some of the Commission's aims through different means.

Protection of the Sovereign's Person

The proposals for protecting the Sovereign demonstrated pragmatic modernisation. The Commission recommended abolishing various archaic categories (such as violating royal ladies or killing the Chancellor and Treasurer) whilst creating straightforward new offences.

Two serious offences would penalise murdering or intentionally injuring the Sovereign, the Sovereign's consort, or the heir to the throne. A less serious offence would cover having near such persons any explosive, weapon or dangerous item with intent to injure or alarm them. Notably, these protections would not extend to other members of the Royal Family.

Significantly, these offences would not constitute "treason" in the technical sense, avoiding the mandatory death penalty which still applied to that category. The Commission carefully avoided commenting on capital punishment, noting this fell outside their remit, but their restructuring effectively created a framework where most serious political crimes would not automatically attract the death penalty.

The Treason Act 1842 remains in force, maintaining its seven-year maximum sentence for various assaults on the Sovereign. The proposed restructuring into modern offences of murder and intentional injury was never implemented. In practice, the ordinary criminal law (murder, assault, possession of weapons) would likely be used today for serious attacks on royalty, with the 1842 Act reserved for less serious incidents. The death penalty question became moot with its abolition for murder in 1965 and for treason in 1998.

The Sedition Question

Perhaps the most radical proposal concerned sedition, where the Commission recommended complete abolition of all sedition offences. This reflected both the uncertain state of the law and doubts about its necessity.

Sedition's legal definition had evolved chaotically through case law. Originally understood broadly as conduct disturbing the state, by 1977 sedition appeared to require an intention to incite violence or public disorder with the aim of disturbing constituted authority. The Commission noted "probably no crime has been left in such vagueness of definition."

The abolition proposal rested on two pillars. First, existing law already covered conduct amounting to sedition through ordinary offences like conspiracy to commit violent crimes, incitement to riot, and unlawful assembly. Second, retaining sedition risked suggesting the conduct was "political" rather than simply criminal, potentially conferring unwarranted legitimacy on violent extremism.

The Commission argued it was better to prosecute violent political action through ordinary criminal law rather than through special political offences carrying implications of martyrdom. This represented a distinctly pragmatic, even cynical, understanding of how to manage political violence: strip it of any special status and treat it as common criminality.

The common law offence of sedition was finally abolished by the Coroners and Justice Act 2009, section 73, which came into force on 12 January 2010. This occurred over thirty years after the Commission's recommendation, suggesting Parliament eventually agreed with their analysis. The abolition attracted remarkably little public attention, reflecting how thoroughly the offence had fallen into disuse. The last prosecution for seditious libel in England had been in 1947, and the last successful prosecution in 1922. By 2009, sedition had become a legal fossil, and its removal simply recognised this reality.

Subversion of the Armed Forces

The paper examined various statutes criminalising attempts to undermine military loyalty, particularly the Incitement to Mutiny Act 1797 and the Incitement to Disaffection Act 1934. These provisions had proved controversial, with critics arguing they unduly restricted free speech, particularly for conscientious objectors to military service.

The Commission recommended repealing the 1797 Act as obsolete but took no position on whether to retain the 1934 Act, recognising this involved political judgements about balancing national security against freedom of expression. If retained, however, the 1934 Act should be clarified to require intent to induce a fundamental breach of duty amounting to breach of allegiance, rather than mere persuasion to minor disciplinary infractions.

This careful avoidance of the free speech question revealed the Commission's limitations. Whilst they could propose technical legal improvements, the fundamental policy choice about how much dissent to tolerate near military installations required political, not legal, expertise.

The Incitement to Mutiny Act 1797 was finally repealed by the Crime and Disorder Act 1998, achieving the Commission's recommendation after twenty years. However, the Incitement to Disaffection Act 1934 remains in force in 2024, despite continued criticism. The Act saw renewed attention during protests against the Iraq War in the early 2000s, when anti-war campaigners distributed leaflets to military personnel. Prosecutions under the Act remain extremely rare, but its continued existence demonstrates Parliament's reluctance to remove powers which, whilst seldom used, might be needed during national emergencies.

The Aliens Question: Remarkably Close To Today

The Commission's treatment of the Aliens Restriction (Amendment) Act 1919 deserves extensive examination, both for the severity of the law itself and the broader questions it raised about wartime measures becoming permanent features of peacetime legislation.

Historical Origins

The Aliens Restriction (Amendment) Act 1919 emerged from the heightened xenophobia and security concerns of the First World War. The original Aliens Restriction Act 1914 had granted extensive powers to regulate foreign nationals during wartime. The 1919 Amendment Act, passed in the aftermath of war during a period of labour unrest and fears of Bolshevik infiltration, made many of these emergency powers permanent and added new provisions specifically targeting political activity by aliens.

Section 3(1) created an offence of remarkable breadth:

If an alien attempts or does any act calculated or likely to cause sedition or disaffection amongst His Majesty's Forces or the forces of His Majesty's allies, or amongst the civilian population, he shall be guilty of an offence under this Act.

The maximum penalty on indictment was ten years' imprisonment, yet the offence could also be tried summarily with a maximum of three months' imprisonment, deliberately excluding the right to jury trial.

Section 3(2) added a further provision:

If an alien promotes or attempts to promote industrial unrest in any industry in which he has not been bona fide engaged for at least two years immediately preceding in the United Kingdom, he shall be guilty of an offence under this Act.

The Commission's Analysis and Critique

The Law Commission's criticism of these provisions, though measured in tone, was devastating in substance. They identified several fundamental flaws.

Absence of Mental Element: The use of "calculated or likely" meant an alien could be convicted without any intention, knowledge, or even recklessness regarding the consequences of their actions. The Commission observed:

for it to be an offence in peacetime to do an act likely to cause disaffection amongst the Forces or the civilian population without any requirement of intention is a remarkable example of legislation which is surely out of date.

This represented an extraordinary departure from normal criminal law principles. Most serious offences require proof of mens rea (guilty mind). Even under the Incitement to Disaffection Act 1934, which applied to British subjects, the prosecution had to prove the defendant acted "maliciously and advisedly". The 1919 Act imposed strict liability for political speech by aliens.

Ambiguity of "Disaffection": The statute never defined "disaffection amongst the civilian population". Presumably this meant reducing loyalty to the government or constitution, but the scope remained unclear. Could criticism of government policy amount to causing disaffection? What about exposing government misconduct? The vagueness created a chilling effect on legitimate political expression by foreign nationals.

The "Calculated" Problem: As the Commission noted in discussing the Police Act 1964, the word "calculated" in criminal statutes creates confusion. Does it mean "designed" or "intended", or merely "likely" or "apt"? Using "calculated" disjunctively with "likely" in the 1919 Act suggested the former meaning, but this remained uncertain. The Commission recommended replacing such archaic terminology with clear modern language.

Industrial Unrest Provision: Section 3(2) was even more problematic. It criminalised aliens promoting industrial unrest in industries where they had not worked for two years, without requiring any intent to harm national security or public order. This appeared designed to prevent foreign labour organisers from assisting British workers during strikes, reflecting the anti-labour and anti-immigrant sentiment of the post-war period.

The provision raised obvious questions about freedom of association and expression. Could a foreign academic write articles supporting trade union rights? Could an exiled labour organiser from another country speak at rallies? The statute's vagueness left such questions unanswered.

Discriminatory Nature: Most fundamentally, the Act applied exclusively to aliens. British subjects could advocate for strikes, criticise the military, or promote radical political change with (relative) impunity under freedom of speech principles. Foreign nationals faced imprisonment for the same conduct. This created a two-tier system of rights based solely on nationality.

The Commission's Recommendation

Given these profound defects, the Commission's recommendation proved unambiguous and emphatic: "It is also our provisional view that the offences in the Aliens Restriction (Amendment) Act 1919 can now safely be repealed."

The word "safely" is telling. The Commission recognised Parliament might fear abandoning any tool potentially useful for national security, however draconian. Their assurance of safety rested on two grounds.

First, by 1977 the provisions had effectively fallen into desuetude. The Commission found no evidence of prosecutions in recent decades. The offences had become dead letters, retained on statute books but never invoked.

Second, other legislation provided adequate protection. The Incitement to Disaffection Act 1934 covered attempts to subvert military loyalty (and applied to everyone, not just aliens). The Public Order Act 1936 addressed threats to public order. Sedition law (however flawed) penalised incitement to violence. Immigration law allowed deportation of foreign nationals whose presence proved "not conducive to the public good". The specific targeting of aliens for political speech served no purpose other legislation could not fulfil.

Blair's Dissolution of the Statute

The Aliens Restriction (Amendment) Act 1919 was finally repealed by the Immigration and Asylum Act 1999, section 169(1) and Schedule 16. This occurred twenty-two years after the Commission's recommendation, demonstrating once again the glacial pace of reform in this area.

The delay is instructive. No evidence suggests the provisions were used during this period. Parliament apparently maintained them from inertia and a vague sense they might prove useful in some hypothetical emergency, rather than from any practical necessity. This reflects a broader pattern in British law: emergency measures, once enacted, prove remarkably difficult to remove even when the emergency has passed and the measures have become obsolete.

The eventual repeal formed part of broader immigration law modernisation rather than a specific response to the Commission's work. The 1999 Act consolidated and updated immigration legislation, providing an opportunity to remove archaic provisions as part of general housekeeping rather than principled reform.

Comparative Context

The 1919 Act's provisions should be understood within the broader context of early twentieth-century attitudes towards aliens and political radicalism. Similar legislation existed in other common law jurisdictions during this period, often inspired by similar fears of foreign subversion.

The United States, for instance, enacted the Alien Registration Act 1940 (Smith Act) criminalising advocacy of violent overthrow of government, with enhanced penalties for aliens. However, American courts gradually circumscribed such legislation through First Amendment protections, requiring proof of incitement to imminent lawless action rather than mere abstract advocacy.

Canada's War Measures Act allowed sweeping detention of aliens during wartime, but these provisions lapsed during peacetime rather than becoming permanent. Australia maintained restrictions on alien political activity until the 1950s, when they were repealed amid recognition of their incompatibility with emerging human rights norms.

Britain's retention of the 1919 Act until 1999 therefore represented unusual longevity for such legislation. The delay in repeal reflected Britain's uncodified constitution and absence of an entrenched bill of rights, meaning Parliamentary supremacy could maintain discriminatory legislation without effective legal challenge.

Human Rights Implications

By the 1970s, the 1919 Act's provisions had become increasingly difficult to reconcile with international human rights law. The European Convention on Human Rights, which Britain had ratified in 1951, guaranteed freedom of expression (Article 10) and freedom of association (Article 11) subject only to necessary restrictions in a democratic society.

Criminalising speech "likely" to cause disaffection without requiring intent, and without clear definition of prohibited conduct, would struggle to meet the "necessary in a democratic society" test. The provisions failed the standards of legality, necessity, and proportionality required for rights restrictions under the Convention.

However, until the Human Rights Act 1998 incorporated the Convention into domestic law, British courts could not strike down incompatible legislation. The 1919 Act therefore remained technically valid despite its questionable Convention-compatibility, another illustration of how Britain's constitutional arrangements allowed anachronistic laws to persist.

The Broader Significance

The aliens provisions of the 1919 Act exemplify several recurring themes in British legal history.

Wartime Measures Becoming Permanent: Emergency legislation enacted during crisis periods often persists long after the emergency has passed. The 1919 Act transformed temporary wartime restrictions into permanent peacetime law, a pattern repeated with anti-terrorism legislation in recent decades.

Reluctance to Surrender Powers: Parliament proves consistently reluctant to repeal powers which, whilst seldom used, might prove useful in future emergencies. The precautionary principle dominates: better to retain unused powers than risk needing them later.

Discrimination Against Non-Citizens: The Act reflected and reinforced a view of citizenship as conferring a superior tier of rights. Non-citizens could legitimately be subject to restrictions on political activity deemed unacceptable for citizens. This attitude persists in modern immigration and terrorism legislation, where foreign nationals face different (often more restrictive) rules than citizens.

The Gap Between Law and Practice: The Act remained enforceable law for decades without being enforced, creating a situation where authorities possessed sweeping theoretical powers never exercised in practice. This raises questions about whether such dormant powers should remain on statute books or be removed to prevent potential future abuse.

Inadequacy of Common Law Protections: Unlike jurisdictions with constitutional protections for speech and association, Britain relied on Parliamentary wisdom to avoid enacting or maintaining oppressive legislation. The 1919 Act demonstrated the limitations of this approach: once enacted, even thoroughly objectionable legislation could persist for eighty years.

Procedural Reforms

Throughout, the paper emphasised the need for clear, modern language accessible to contemporary juries. The drafting of new offences should avoid archaic terms like "maliciously and advisedly" or ambiguous phrases like "duty or allegiance." The law should state plainly what conduct was prohibited and what mental state was required.

The Commission also noted the need to clarify who was subject to each offence, avoiding the confused common law rules about allegiance which had required complex judicial interpretation. Modern citizenship law provided clear categories making such precision possible.

Limited progress occurred on procedural reform. The Criminal Law Act 1967 had already simplified treason trial procedures, removing the requirement for two witnesses to the same overt act. The Coroners and Justice Act 2009 made further procedural changes alongside abolishing sedition. However, no comprehensive modernisation of language occurred for treason offences, which retain their mediaeval terminology.

What Was Not Implemented

The fate of the 1977 proposals reveals several patterns in British legal reform.

Parliament proved willing to abolish obsolete offences (sedition, incitement to mutiny, the aliens provisions) but unwilling to undertake comprehensive reconstruction of treason law. Removing dead letters from statute books required less political capital than replacing ancient but still-functioning legislation with modern alternatives.

Rather than modernising treason law, Parliament created parallel frameworks through terrorism legislation. The Terrorism Act 2000 defined terrorism broadly to include use or threat of action designed to influence government or intimidate the public for political, religious or ideological purposes. This essentially created modern political offences without touching the ancient treason statutes.

So long as treason carried the death penalty, comprehensive reform remained politically toxic. Opposition to capital punishment and support for modernising treason law became entangled. Only after the death penalty's final abolition in 1998 did reform become theoretically feasible, though by then Parliament had lost interest.

Britain's uncodified constitution and reverence for constitutional continuity created reluctance to tamper with fundamental laws, even when they had become archaic. Treason law, intimately connected with monarchy and sovereignty, attracted protective conservatism despite its practical obsolescence.

Major reforms to security law occurred in response to specific crises (Northern Ireland troubles, 9/11, 7/7 bombings) rather than through systematic review. The Law Commission's thoughtful proposals, unconnected to any immediate emergency, lacked the political momentum such crises provide.

Modern Relevance

The 1977 Working Paper's analysis remains surprisingly relevant nearly five decades later. Several issues it identified continue to generate contemporary debate.

Questions about who owes duties to the state, and on what basis, have intensified with globalisation and mass migration. Recent cases of British citizens joining ISIS raised questions about allegiance and treason charges, though prosecutions ultimately relied on terrorism legislation rather than the Treason Act 1351.

The Commission's proposal for a peacetime offence of violently attacking constitutional order resonates amid contemporary concerns about democratic backsliding and violent extremism. However, rather than creating a specific treason-type offence, Britain has relied on terrorism legislation and ordinary criminal law.

Debates about where to draw lines between protected political speech and criminal incitement to violence continue. The Commission's nuanced discussion of these boundaries in the context of sedition and military subversion offers useful historical perspective on perennial questions.

The fundamental challenge the Commission addressed—how to modernise laws rooted in radically different social and political structures—remains relevant across many areas of English law, from property to criminal procedure.

Historical Significance

This working paper represents a crucial moment in English legal development: the point at which ancient feudal concepts of personal loyalty to the monarch were being openly questioned in favour of protection of constitutional democracy. The proposals sought to preserve what remained valuable in treason law (protection against armed overthrow of legitimate government) whilst discarding obsolete elements rooted in medieval power.

The document also reveals tensions within liberal democracy about political offences. Should the state treat violent political action as a special category of crime, or simply as ordinary criminality? Should attempts to undermine military morale enjoy free speech protection, or does national security require their prohibition? The Commission's careful navigation of these questions, and their occasional retreat to claiming certain matters lay outside their expertise, demonstrates the difficulty of separating legal from political judgement.

The subsequent history of partial, delayed, and incomplete implementation demonstrates both British constitutional conservatism and the practical difficulty of wholesale reform of fundamental laws. Parliament proved willing to abandon completely obsolete provisions (sedition) but unwilling to reconstruct still-relevant frameworks (treason) even when their inadequacy was apparent.

Ultimately, the paper proposed transforming treason from a crime against the monarch's person into a crime against constitutional order, from feudal obligation into democratic protection. Whether this transformation would have proved successful remains unknown, as the specific proposals were never implemented. Nevertheless, the document remains valuable both as a historical record of legal thinking in the 1970s and as a thoughtful analysis of how ancient law might be modernised without losing essential protections.

The Commission's work also illustrates the limitations of expert bodies proposing rational reforms. Despite producing careful analysis and sensible recommendations, they could not compel Parliamentary action. Reform occurred only when politically convenient (usually as part of larger legislative packages) or when provisions had become so obsolete their retention became embarrassing. The story of the 1977 proposals is thus partly a story about the gap between expert advice and political will, between what lawyers think should happen and what Parliament actually does.