The assizes, or courts of assize, were periodic courts held around England and Wales until 1972, when together with the quarter sessions they were abolished by the Courts Act 1971 and replaced by a single permanent Crown Court. The assizes exercised both civil and criminal jurisdiction, though most of their work was on the criminal side. The assizes heard the most serious cases, most notably those subject to capital punishment or, later, life imprisonment. Other serious cases were dealt with by the quarter sessions, while the more minor offences were dealt with summarily by justices of the peace in petty sessions.

The courts of quarter sessions or quarter sessions were local courts that were traditionally held at four set times each year in the Kingdom of England from 1388; they were extended to Wales following the Laws in Wales Act 1535. Scotland established quarter sessions in the 17th century. Quarter sessions were also established in Ireland and British colonies overseas.