Historic Manx jury charged with making presentments within each of the six sheadings.

The Commissioners of Inquiry in 1792 described the Great Inquest as one of several juries peculiar to the Island, alongside the Setting Quest and juries of trespass and inquiry.

Each sheading had a Great Inquest of twelve men returned by the Coroner. At the time described by the Commissioners the jurors served for six months, being sworn at the meetings of the Common Law Courts in May and October.

The Inquests attended the court of the sheading to which they belonged. A Deemster administered their oath and delivered a charge explaining the matters on which they were expected to make presentments.

The Commissioners linked these duties with the old customs entered in the Manx statute book in 1577. The Great Inquests were required to present matters specified there and to return their verdicts and presentments to the Deemsters whenever required.

Their role extended into the management of land and local resources. The constitutional notes explain that when the Governor granted licences to enclose land from the wastes or demesnes, the grant remained subject to approval by the Great Inquest in matters affecting public roads, waters and turbary rights.

The institution changed over time. A later editorial note records that Great Enquests served for a full year and were sworn at the October Common Law Courts, rather than serving the six-month terms described in the original 1792 report.

The Great Inquest also remained part of later legal procedure. Nineteenth-century legislation continued to refer to traverses from its verdicts and provided for new trials before a Deemster and a twelve-man jury where necessary.