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Good Friends or Neighbors: Compurgators in Medieval Times

The following is a guest post by Dante Figueroa, a senior legal information analyst at the Law Library of Congress. Dante has contributed a number of In Custodia Legis blog posts, including on The Rehabilitation of Dante Alighieri, Seven Centuries Later, Resources and Treasures of the Italian Parliamentary Libraries,  Legislation Protecting Italian Cultural Heritage, Proposed Anti-Sect Legislation in Italy: An Ongoing Debate, and The Crime of Desertion in Roman Law.


While reviewing new Italian and canon law titles recently, I came across several books on the topic of medieval secular and canonical criminal procedure. One of them, Il giuramento di innocenza nel processo canonico medievale: Storia e disciplina della “purgatio canonica” (The Oath of Innocence in the Medieval Canonical Procedure: the History and Discipline of the “Canonical Purgation”) written by Antonia Fiori in 2013, caught my eye. The book made me think about the importance of having good friends and how the value of true friendship should not be underestimated, particularly in European society in the Middle Ages. One of the ultimate commitments made by friends at that time was the taking of an oath attesting to the character or credibility of a friend who was accused of committing a crime (compurgation).

Antonia Fiori, Il giuramento di innocenza nel processo canonico medievale: Storia e disciplina della “purgatio canonica” (The Oath of Innocence in the Medieval Canonical Procedure: the History and Discipline of the “Canonical Purgation.”) [Photo by Ruth Levush.]

Trial Procedure under Canon Law

Trials in the Middle Ages in Europe usually started with the accused (purgandus) taking an oath of innocence as it was “standard procedure to question a suspect under oath before any charges were stated.” (Henry Ansgar Kelly, Inquisitions and other trial procedures in the Medieval West (2001), at 1000). The oath was followed by compurgation by a specific number of the accused’s peers or equals. Compurgation was a method initially adopted by canon law from the Germanic churches. (Fiori, supra, at 371). Its use was later expanded to regular courts of law throughout Europe. Compurgation was used in English law until it was superseded by the jury system; however, the system was never extended to the British colonies.

General Description of Compurgators

The Latin compurgare roughly means “to pay jointly with another.”  Since the 6th century, the Catholic Church demanded from its penitents an “oath of purgation” (purgatio canonica), meaning a testimony to the innocence of clerics accused of sins or crimes. The oath of purgation trumped any evidence of guilt and gave the accused a canonical licentia, that is an absolution or non-guilty judgment. The oath of purgation, however, was only allowed for free men who had not demonstrated habitual criminal conduct. (Fiori, supra, at 131—132).

Rules Applicable to Compurgators in Medieval Canonical Oaths

The compurgators (also called sacramentales, aidos, testes, or iuratores) reflected the importance of the support of the respective social group towards one of their own. Compurgators were called to testify not on the truth of the facts involved, but on the credibility of the accused and his incapacity to commit a crime. The number of compurgators varied between twelve and submultiples of twelve. From the ninth century onward, canon law demanded twelve compurgators for a bishop, six for a priest, and three for a deacon. Canonical judges enjoyed broad discretion to vary the number of compurgators in a specific case. (Id. at 114—371) . Most importantly, compurgators had to be a simil (similar or belong to the same social class) of the accused. Therefore, if the accused was a priest, the compurgators had to be priests, and likewise for a deacon or a bishop. (Id. 115-116).

Compurgators faced the moral, legal, and religious risk of conviction for taking an oath on behalf of those who did not enjoy the support of their communities. They attested to the accused’s innocence and hence the absolution of the accused. Fleeing from the court was considered an assumption of guilt; hence, if the accused fled, the compurgators had to satisfy the penalty. (Id. at 117).  Over time, strict canonical rules were enacted to prevent clerics from concluding and benefiting from fraudulent reciprocal agreements to serve as co-compurgators and avoid purgatio ad ordalia (trial by ordeal). (Id. at 129).

Criticism of the Institution of Compurgation

The use of compurgators in medieval canonical procedures against clerics was not without controversy. The central criticism was that canonical courts denied the accused the possibility of a simple oath of innocence; however, this was based on the erroneous assumption that a priest could not make an oath of innocence without the presence of compurgators. (Id. at 134-136).

Another heated debate in medieval canonical law was whether compurgators should be admitted to testify to the truth rather than to the credibility of the accused. Much was at stake in this debate since the church traditionally made a distinction between testimonies of guilt and testimonies of credibility. The oath of purgation (innocence) was afforded a sacramental value while a witness’s testimony was an evidentiary measure of guilt or innocence. The admissibility of compurgators to demonstrate not only credibility (testes idonei) but also innocence (testes purgationem), previously restricted to the accused, started to slowly make inroads in the canon law of the High Middle Ages. (Id. at 137).

The Appointment of Compurgators

The role of compurgator was restricted to those who understood and valued such responsibility. Canon law limited the availability of compurgation to cases where the guilt of the accused had not been or could not be proven (ubi delictum est probabile, purgatio non indicitur.) Persons familiar with the accused (boni ac vicini), not prone to perjury (periculum animae), and not suspected of having strong feelings about or economic ties to the accused were the natural candidates for compurgators. (Id. at 341-352).

Over the centuries, judicial arbitrium (discretion) was also carried over to purgation, meaning the power of the judges was extended to the power to choose the punishment. This evolved to provide the local bishop with the discretion to demand and choose a number of compurgators to take an oath on behalf of the accused in a given case. (Id. at 113).  Later on, the ecclesiastical judge, not the accused, ultimately appointed the compurgators (arbitrium iudicis). (Id. at 359, 360 & 362).

Additional bibliographical resources on compurgation at the Library of Congress include:


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