Thomas of Sibthorpe, a Nottinghamshire clergyman and chancery clerk, prospered under the regime of Edward II and his favourite Hugh Despenser the younger, and again under Edward III, when he also became a clerk of parliament and a justice of assize and of the peace. In 1326 he established at Sibthorpe a college of chantry priests to pray for his soul and those of others; it was twice expanded and more lavishly endowed, in 1335 and 1343. He appointed a keeper or warden to take charge of the college, and used all available legal means to ensure that the endowment was firmly appropriated to the warden, who was obliged periodically to render him accounts. In 1351 the third warden, Robert of Kneeton, aided by others, allegedly murdered him in order to avoid rendering such an account. They were tried at a Nottingham gaol delivery, convicted of seditious killing and sentenced to be drawn and hanged, the punishment reserved for traitors, because the victim was a royal clerk and justice. The circumstances of Sibthorpe’s death may have had a significant effect on the terms of the first Great Statute of Treasons, adopted by parliament only a few months later, and presumably incorporating the views of the most senior judges in England.