The Assize of Clarendon

King Henry II of England had problems. The period known as The Anarchy was over, but the mercenaries employed during it were causing trouble in England now that no one was paying them. "Crusades Fever" was rampant, and aristocrats were leaving their lands for years at a time to liberate the Holy Land; when they returned, they might find someone else farming their estates without permission—and no office of land management that kept records as to who was the rightful owner. And, of course, the Church was doing as it pleased regarding the law, exercising sole authority over its clergy rather than allow them to be bound by civil laws.

Henry needed to put some order onto this chaos. We have already seen (later in his reign) the Assize of Arms. The major instrument of establishing new policies was the Assize of Clarendon in 1166. It was an attempt to establish the rule of law based on evidence and analysis rather than Trial by Ordeal, and to rest final authority with the Crown and its representatives.

It made certain that sheriffs kept records of any criminals in their territories, and that sheriffs would notify other sheriffs of criminals that fled in their direction, to be captured and held. A cleric who was found guilty in an ecclesiastical court was stripped of his office and turned over to the civil court. Compurgation was no longer sufficient as a defense in a felony. Sheriffs had to respond to requests by the "itinerant justices" (the "justices in eyre") sent around by the king.

One important innovation that modern law historians make note of is the first part of Clarendon:

1. In the first place the aforesaid king Henry, by thee counsel of all his barons, for the preservation of peace and the observing of justice, has decreed that an inquest shall be made throughout the separate counties, and throughout the separate hundreds, through twelve of the more lawful men of the hundred... [link]

This is seen as the first step to "Trial by Jury" with  jury of twelve of your peers chosen to analyze a case and help pass judgment.

Eyres

An "eyre" (Middle English, from Old French eire from Latin iter, "journey") was "a circuit court held in medieval England by a judge (a justice in eyre) who rode from county to county for that purpose." (New Oxford American Dictionary). The justices in eyre, sent from Westminster to all counties (all but two that is; see below), would hear and rule on crown pleas (criminal offenses), and civil pleas (lawsuits).

Eyres were declared in the Assize of Clarendon in 1166, put in place by the rule-loving Henry II (1133 - 1189)—who wanted to get away from solutions that involved Trial by Combat or Trial by Ordeal—but we have no records of the eyres from that decade. By the end of the century, justices in eyre were required to keep careful records so that sheriffs knew from whom and how much in fines they were supposed to collect. The resulting "eyre rolls" are rolls of parchments stitched together, filled with Latin abbreviations and legal terminology.

Durham and Chester were exempt from the justices in eyre. The king had no jurisdiction there, because they were palatinates, ruled by a local palatine [Latin: "of the palace"], a figure who had jurisdiction that normally belongs to a king. Durham and Chester were under the control of their bishops, and eyres could only be conducted there if a bishop were dead and his successor not yet appointed.