Compurgation, also called trial by oath, wager of law, and oath-helping, was a defence used primarily in medieval law. A defendant could establish their innocence or nonliability by taking an oath and by getting a required number of persons, typically twelve, to swear they believed the defendant's oath. The wager of law was essentially a character reference, initially by kin and later by neighbours (from the same region as the defendant), often 11 or 12 men, and it was a way to give credibility to the oath of a defendant at a time when a person's oath had more credibility than a written record. It can be compared to a legal wager, which is the provision of surety at the beginning of legal action to minimize frivolous litigation. Compurgation was found in early Germanic law, in early French law (très ancienne coutume de Bretagne), in Welsh law, and in the English ecclesiastical courts until the seventeenth century. In common law it was substantially abolished as a defence in felonies by the Constitutions of Clarendon in 1164. The defence was still permitted in civil actions for debt and vestiges of it survived until its statutory repeal at various times in common law countries: in England in 1833, and Queensland at some point before the Queensland Common Practice Act of 1867 which makes direct reference to the abolition of wager of law. "Wager of Law, obsolete for centuries" was "a living fossil ... a dead letter statute" and was abolished in England in 1833. Etymology The word compurgation is composed of Latin, com "with" and purgare "to make clean, cleanse, excuse". Latin com- is also an intensifier and turns a word into the superlative form, so compurgation, by etymology, means "to thoroughly clean or excuse". Origins The procedure in a wager of law is traced by Blackstone to the Mosaic law, ; but it seems historically to have been derived from the system of compurgation, introduced into England from Normandy, a system which is now thought to have had an appreciable effect on the development of the English jury. It also has some points of resemblance, perhaps some historical connexion, with the sponsio and the decisory oath of Roman law, and the reference to oath of Scottish law. Wager of law, wager of battle and trial by ordeal The wager of law, also called compurgation, is an old legal practice, dating back