Justice in eyre

In English law, the Justices in eyre were the highest magistrates in medieval forest law, and presided over the court of justice-seat, a triennial court held to punish offenders against the forest law and enquire into the state of the forest and its officers. (Eyre, meaning "circuit", refers to the movement of the court between the different royal forests.)

Technically, the two justices were referred to as citra and ultra Trent (on the same side or across the River Trent), depending on where the royal court was held at the time, but are usually referred to in absolute geographical terms north and south. The holders were originally referred to as "justice of the forest" until the reign of Henry VIII, when the title of "justice in eyre" came into use, except from 1311–1397, when they were usually styled "warden of the forest". However they were still called "justices in eyre" in the Treason Act 1351 (under which it was high treason to kill them in the execution of their office). In 1397, the Commons plea that the Articles be pardoned except for pleas of land, quo warranto, treason, robbery, or other felonies.

Henry de Bracton says that it was the practice of the justices to retire and confer with the busones of the county. In these busones we can see the persons whose names appear in the commissions of gaol delivery, oyer and terminer, and who were in later days, as justices of the peace, to rule the county.

With the decay of forest law and the lapse of the court of justice-seat, the post became a sinecure. A statute of 1817 abolished it after the decease of the current holders.

The arrangement of justices north and south of Trent did not become fixed until 1236.

...
Wikipedia