In 1506 Henry VII granted the "Great Charter" to Chester (see: Charters). This made the City of Chester (apart from Chester Castle) a county separate from the rest of Cheshire.
The Mayor and Sheriffs were invested with authority to hold a Court in the Common Hall of the City for the trial of offences and claims of all kinds (except for treason) arising within the City, its suburbs, and hamlets, and Port-mote and Crown-mote courts were to be held before the Mayor. The forfeited goods of felons were to be the property of the citizens, who were also freed from the payment of all customs except those on wine and iron. The management and regulation of the River Dee fisheries was vested in the Mayor and Sheriffs, as well as the control of the city markets.
The twenty-four Aldermen were automatically justices of the peace by virtue of their office. As might be expected, putting the legal process into the hands of a largely self-electing body representing the mercantile community was a recipie for the development of vested interest.