The first Justices of the Peace (JPs) were appointed under a parliamentary statute of 1327. They were senior members of local communities, chosen more for their local importance than their legal expertise.
Their main purpose was to uphold law and order in towns and rural areas, and to arrest and hold offenders charged with serious crime. Wrong-doers would then be referred for trial at the assizes.
Another statute of 1363 directed that justices were to hold sessions four times a year. In each county the quarter sessions were held in the main towns.
During the 18th century, as the number of capital, or hanging, offences grew considerably, JPs sitting in quarter sessions referred increasing numbers of offenders to trial at the assizes. Those charged with certain types of lesser crime would be tried at the quarter sessions by two or more JPs in the presence of a jury.
In their own districts JPs were also responsible for hearing cases involving minor crime, such as petty theft, fighting and drunkenness. JPs sat in pairs or small groups (often referred to as 'the bench'), or singly, to judge these and other minor offences without a jury.
These summary courts were held regularly, and were known as petty sessions. By the early 19th century each county or town was divided into a number of petty sessions areas.
The courts were commonly known as magistrates' courts. It was the task of JPs to implement justice in accordance with a growing body of regulations laid down by Parliament.
In addition to their judicial function JPs were also the unpaid local representatives of central government.