Bracton's discussion of Frankpledge

Frankpledge was a system of compulsory suretyship. its essential characteristic was the the compulsory sharing of responsibility among persons connected through kinship, or some other kind of tie such as an oath of fealty to a lord or knight. This kind of bond was typical of the Anglo-Saxon period. In the late Anglo-Saxon period and continuing into the Norman (c.1166 at time of Henry II) each commoner (unless part of the household of a lord) was required
to be a member of a tithing -- a group of "ten" who formed a frankpledge.

The group was jointly responsible for ensuring that any of its members accused of crime appeared at his trial. If the man did not appear, the entire group could be amerced (fined). Note that the Normans transformed the institution. In the Anglo-Saxon times, the tithing was more akin to a posse. What was added was the requirement that each man must have a pledge. An accused was required to provide a guarantee for his appearance in court to answer a
charge or later for complying with a judgment. "Pledges" may be a man's lord, or kin. If the principle failed in his duty, the pledge paid the injured, or lost property. Note that pledged may also act as compurgators (men who attested to the good character of an accused and thereby "cleared" him -- witness proof).  This is the precursor to our notion of bail.

Now, in the Anglo-Saxon period, the tithing group and the locating of pledges was not linked together. An accused was free to find his pledges where he did. Though from early on in the Anglo-Saxon period, we find edicts that lords were to serve as pledges for the men who owed them an oath of fealty. Immediately after the conquest, however,  William faced sporadic rebellion. Hence, he imposed a fine (the murdrrum fine) on any hundred where a dead
Norman was found unless the killer was promptly produced.
The idea of the collective fine was expanded. By 1166, everyman in a tithing was compelled to be a pledge for the appearance before the king's justice of every other member of the tithing. This must have meant that at times a tithing member was responsible for "arresting" and holding an accused for again, there were no jails and no police.
The Frankpledge was the closest to a policing system. Hence, what was once a group of comrades, and a system of pledging in faith for an accused, became corrupted into a system of neighbor bound to spy on neighbor. The Norman sheriff took view of the frankpledge, that is heard accusations. And if the accused did not later appear, the frankpledge was amerced. By the reign of Henry 1 (1100-1135), the Sheriff traveled throughout his county, going into each hundred twice a year on his "tourn" to accomplish this viewing.
The frankpledge was not imposed on every county, only 30 of 40. In some areas it was impossible such as where Welsh lived. Women and children did not belong to a Frankpledge, some freemen with substantial property, clergy, the mentally ill, lords or others who were in the "mainpast" -- care and shelter -- of a responsible householder. Note that women who were without kin were considered to be not in mainpast, and hence to be "waifed."
From the late 1200s, the Frankpledge began to fall into decay. There were complaints that the Sheriff abused his power often for financial gain.  So too, the royal power had an interest in curbing the power of the sheriff. Originally, he had the power to take presentment, but by 1166  this was done by itinerant royal justices. Nevertheless, from the 1100 until the 1300, this was the way control over crime was organized. It means that our notion of bail, release, and pledging for another's appearance, as well as duty to inform on a neighbor was not pre-determined but rather was the outcome of a particular way in which people grouped (in villages aroud the fields) and of an invasion by one people (the Normans) into the land of another (the Anglo-Saxons).
After 1300, the Sheriff continued to handle more petty matters such as dishonest weights and measures, the sale of diseased food and so forth. Here the Sheriff acted as judgment finder, for the accusation of the Chief tithing man was taken as proof. A fine would be levied which the Sheriff kept. The system of frankpledge also was used by manorial courts. Significantly, in the later Middle Ages, some of the tithingmen began to be referred to as Constables and took on some extra duties of governing in addition to the general duties that came with the ancient

Written by Professor Trisha Olson, Cumberland School of Law