missions for trying a
single cause, or for holding a single term of a court, or for making a
single circuit; which, being done, their commissions expired_. The king,
therefore, could, _and undoubtedly did, appoint any individual he
pleased, to try any cause he pleased, with a special view to the
verdicts he desired to obtain in the particular cases_.

This custom of commissioning particular persons to hold jury trials, in
_criminal_ cases, (and probably also in _civil_ ones,) was of course a
usurpation upon the common law, but had been practised more or less from
the time of William the Conqueror. Palgrave says:

"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