According to the law in force, it is treason felony to "compass, imagine, invent, devise, or intend":   In addition to the Acts of 1351, 1703, and 1848, two additional Acts passed by the old Parliament of Ireland apply to Northern Ireland alone. The following is also treason: (Note that although the Irish Act of Supremacy (Ireland) 1560 is still in force, it is no longer treason to contravene it.) In England, there was no clear common law definition of treason; it was for the king and his judges to determine if an offence constituted treason. Thus, the process became open to abuse, and decisions were often arbitrary. For instance, during the reign of Edward III, a knight was convicted of treason because he assaulted one of the king's subjects and held him for a ransom of £90. It was only in 1351 that Parliament passed legislation on the subject of treason. Under the Treason Act 1351, or "Statute of Treasons", which distinguished between high and petty treason, several distinct offences constitute high treason; most of them continue to do so, while those relating to forgery have been relegated to ordinary offences. First, it was high treason to "compass or imagine the death of our Lord the King, of our Lady his Queen, or of their eldest son and heir." The terms "compass or imagine" indicate the premeditation of a murder; it would not be high treason to accidentally kill the sovereign or any other member of the Royal Family (though someone could be charged with manslaughter or negligent homicide). However it has also been held to include rebelling against or trying to overthrow the monarch, as experience has shown that this normally involves the monarch's death. The terms of this provision have been held to include both male and female sovereigns, but only the spouses of male Sovereigns. It is not sufficient to merely allege that an individual is guilty of high treason because of his thoughts or imaginations; there must be an overt act indicating the plot. A second form of high treason defined by the Treason Act 1351 was having sexual intercourse with "the King's companion, or the King's eldest daughter unmarried, or the wife of the King's eldest son and heir." If the intercourse is not consensual, only the rapist is liable, but if it is consensual, then both parties are liable. Anne Boleyn and Catherine Howard, wives of Henry VIII, were found guilty of treason for this reason. The jurist Sir William Blackstone writes that "the plain intention of this law is to guard the Blood Royal from any suspicion of bastardy, whereby the succession to the Crown might be rendered dubious."