High Treason in The United Kingdom - Liability

Liability

As a general rule, no British criminal court has jurisdiction over the Sovereign, from whom they derive their authority. As Sir William Blackstone writes, "the law supposes an incapacity of doing wrong from the excellence and perfection ... of the King." Furthermore, to charge the sovereign with high treason would be inconsistent, as it would constitute accusing him of disloyalty to himself. After the English Civil War, however, Charles I was tried for treason against the people of England. His trial and execution were irregular; they were more accurately products of a revolution, rather than a legal precedent, and those responsible were themselves tried for treason after the monarchy was restored (see List of regicides of Charles I). However, a person who attempts to become the Sovereign without a valid claim can be held guilty of treason. Consequently Lady Jane Grey was executed for treason for usurping the throne in 1553.

An alien resident in the United Kingdom owes allegiance to the Crown, and may be prosecuted for high treason. The only exception is an enemy lawful combatant in wartime, e.g. a uniformed enemy soldier on British territory.

A British subject resident abroad also continues to owe allegiance to the Crown. If he or she becomes a citizen of another state before a war during which he bears arms against the Crown, he or she is not guilty of high treason. On the other hand, becoming a citizen of an enemy state during wartime is high treason, as it constitutes adhering to the sovereign's enemies.

Insane individuals are not punished for their crimes. During the reign of Henry VIII, however, it was enacted that in the cases of high treason, an idiot could be tried in his absence as if he were perfectly sane. In the reign of Mary I, the statute was repealed.

The Treason Act 1495 provides that in a civil war between two claimants to the throne, those who fight for the losing side cannot be held guilty of a crime merely for fighting against the winner.