"The frequent absence of William from his insular dominions occasioned another mode of administration, _which ultimately produced still greater changes in the law_. It was the practice of appointing justiciars to represent the king's person, to hold his court, to decide his pleas, to dispense justice on his behalf, to command the military levies, and to act as conservators of the peace in the king's name.[95] ... The justices who were assigned in the name of the sovereign, and whose powers were revocable at his pleasure, derived their authority merely from their grant.... Some of those judges were usually deputed for the purpose of relieving the king from the burden of his judicial functions.... The number as well as the variety of names of the justices appearing in the early chirographs of 'Concords,' leave reason for doubting whether, anterior to the reign of Henry III., (1216 to 1272,) _a court, whose members were changing at almost every session, can be said to have been permanently constituted. It seems more probable that the individuals who composed the tribunal were selected as suited the pleasure of the sovereign, and the convenience of the clerks and barons_; and the history of our legal administration will be much simplified, if we consider all those courts which were afterwards denominated the Exchequer, the King's Bench, the Common Pleas, and the Chancery, _as being originally committees, selected by the king when occasion required_, out of a large body, for the despatch of peculiar branches of business, _and which committees, by degrees, assumed an independent and permanent existence_.... Justices itinerant, who, despatched throughout the land, decided the 'Pleas of the Crown,' may be obscurely traced in the reign of the Conqueror; _not, perhaps, appointed with much regularity, but despatched upon peculiar occasions and emergencies_."--_1 Palgrave's Rise and Progress_, &c., p. 289 to 293. The following statute, passed in 1354, (139 years after Magna Carta,) shows that even after this usurpation of appointing "justices" of his own, to try criminal cases, had probably become somewhat established in practice, in defiance of Magna Carta, the king was in the habit of granting special commissions to still other persons, (especially to sheriffs,--_his_ sheriffs, no doubt,) to try particular cases: