Usually twice each year, judges of the King's Common Law courts at Westminster were divided into groups ("commissions") who then traveled on several circuits to hold sessions--the "assizes"--in some 50 provincial towns. Sessions before these judges allowed prisoners accused of felony to be tried locally, without the expense and inconvenience of transport to the capital. Juries for civil disputes could also be summoned before the assize judges, by writs of nisi prius, in order to avoid the cost and difficulty in convening 12 people to give their verdict at Westminster. In addition to their judgment of crimes and adjudication of suits, the assize judges were also responsible for announcing, supervising, and enforcing various administrative orders from the king and Privy Council. Deliberately cultivating pomp and solemnity, the judges served to reinforce the authority and dignity of the crown in the counties.

The following documents relating to Assizes in the mid-seventeenth century were edited by J.S. Cockburn, Somerset Assize Orders, 1640-1659 (From: Butter and Tanner, 1971).