650 years of treason law

* 1351 The Treason Act was passed by the English Parliament during the reign of Edward III, shortly after the start of the Hundred Years' War against France. It established offences of high treason, punishable by execution and the forfeiture of all property to the Crown, and of petty treason.

A person was guilty of high treason if he plotted the death of the sovereign, waged war against the crown or gave "aid and comfort" to the monarch's enemies.

Petty treason was defined as offences against a person's superior, such as a servant killing their master or a wife her husband.

* 1535 Sir Thomas More, who had been Henry VIII's Lord Chancellor was found guilty of treason. He clashed with the king over his desire to break with Rome and was prosecuted over his refusal to accept Henry's claim to be head of the Church of England. The following year Anne Boleyn, Henry's second wife, was also executed for treason and adultery.

* 1606 Guy Fawkes and his fellow Gunpowder Plot conspirators were hung, drawn and quartered after being caught attempting to blow up King James I at the opening of the 1605 session of Parliament.

* 1848 As revolutions swept across Europe, the Treason Felony Act made it an offence, punishable by life imprisonment, to advocate abolition of the monarchy, even by peaceful means, in print. An attempt to repeal the law two years ago failed, so it still technically stands.

* 1916 The Dublin-born Sir Roger Casement had been knighted by George V for his work with the Colonial Service. But he became active in the Irish Republican movement and was arrested off the coast of Co Kerry with a shipload of German arms for the Easter Rising. A campaign to save his life failed and he was hanged four months later.

* 1946 William Joyce, popularly known as Lord Haw-Haw, who broadcast Nazi propaganda to Britain during the Second World War, became the last person to be hanged for treason. He was found guilty on three counts of assisting or giving comfort to the "King's enemies".

* 1998 The death penalty for treason was finally abolished. The last working gallows in Britain had been quietly put out of commission five years earlier.