The courts of assize, or assizes , 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, which were committed to it by the quarter sessions (local county courts held four times per year), while the more minor offences were dealt with summarily by justices of the peace in petty sessions (also known as magistrates' courts).