Definition
A conjurator was a person who swore an oath jointly with others, or who was bound by a common oath alongside fellow oath-takers. The term appears in two distinct procedural contexts in old English law:
1. As a compurgator: a person who swore alongside an accused party to affirm that party's oath of innocence, lending the weight of their own oath-bound credibility to support the defendant's denial of wrongdoing. In this sense, conjurators were the sworn helpers who made compurgation possible.
2. As a conspirator or co-swearer in a more general sense: a person united with others through a shared oath, which in certain contexts carried the negative connotation of unlawful combination or conspiracy.
The term is archaic and has no living application in modern law.
---
Common Language
Modern common usage (Wiktionary): A person who swears an oath along with others.
Historical common usage (Webster's 1913): One who swears or is sworn with others; one bound by oath with others; a compurgator.
The common and legal meanings are unusually close here, but the legal context adds critical nuance. In ordinary usage, a co-swearer is simply someone who takes an oath at the same time as another. In legal usage, the conjurator's oath had formal procedural weight — it was not merely simultaneous swearing but oath-based testimony supporting another party's legal position, or alternatively, oath-based association that could establish unlawful combination. The same word thus described both a legitimate defense mechanism and a potential basis for criminal liability.
---
Common Confusion
Conjurator and compurgator overlap substantially but are not identical. Compurgator is the more specific and better-preserved term: it refers exclusively to the oath-helper in the trial procedure of compurgation. Conjurator is the broader term, encompassing any person bound by oath with others, which includes compurgators but also extends to persons united by oath in other capacities — including conspirators. A compurgator is always a conjurator in the oath-binding sense, but not every conjurator is functioning as a compurgator. Researchers encountering conjurator in historical sources should examine context carefully before assuming a compurgation proceeding is involved.
---
Why It Matters in Research
Conjurator is a term that surfaces almost exclusively in historical legal materials dealing with pre-Norman and early common law procedure. Researchers working in medieval English legal records, ecclesiastical court documents, or treatises on the ancient law of proof will encounter it as part of the compurgation framework — a system in which the defendant's oath was supported or undermined by the oaths of neighbors or associates.
The dual valence of the term — legitimate oath-helper versus conspiratorial co-swearer — creates a genuine interpretive trap in historical sources. A document referring to conjurators in a criminal context may be describing either compurgators supporting a defense, or co-conspirators united by oath in an unlawful purpose. The surrounding procedural context must resolve which meaning applies.
The term does not appear in modern statutory or case law and will not be found in contemporary legal materials. Its research value is confined to the historical corpus: year books, plea rolls, Bracton, Glanvill, and later antiquarian treatises. Black's Law Dictionary entries across editions are virtually identical, indicating the term's meaning was fixed and uncontested by the time legal lexicography formalized it — there was no live interpretive dispute to record.
Researchers tracing the history of proof and credibility in the common law tradition will want to read conjurator alongside the broader compurgation and wager of law materials. The term also connects to the history of conspiracy, since oath-bound combinations were among the earliest legally cognizable forms of concerted wrongdoing.
---
Historical Dictionary Support
Both editions of Black's Law Dictionary offer identical definitions: "one who swears or is sworn with others; one bound by oath with others; a compurgator; a conspirator." Webster's 1913 matches closely, omitting only the conspirator sense — a telling difference. The legal dictionaries preserve the dual meaning (legitimate and unlawful), while the general dictionary retains only the neutral procedural sense. This divergence suggests that the conspiratorial connotation was recognized as distinctively legal rather than part of common understanding.
None of the available sources elaborate on the procedural mechanics, the number of conjurators required for compurgation, or the standards governing who could serve in this role. For those details, researchers must go beyond the dictionary sources to primary and treatise literature on compurgation itself.
---
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Compurgation; Wager of Law; Conspiracy (Historical Development)
---