Royal justices were judges in medieval England with the power to hear pleas of the Crown.
They were roving officials of the king of England, sent to seek out notorious robbers and murderers and bring them to justice.
[3] The laws of Cnut (r. 1016–1035) reserved the most serious crimes, such as murder and treason, to the king's jurisdiction as pleas of the Crown.
Henry I (r. 1100–1135) organised the royal justices into judicial circuits,[5] and his chief justiciar would send justices on periodic general eyres to investigate crown pleas and levy fines for dereliction of duty.
This is the origin of the modern system where High Court judges go "on circuit" to hear serious cases.