Definition
In historical legal usage, *conjurare* (Latin) means to swear together, or to combine and confederate under oath. It describes the act by which two or more persons bind themselves jointly by solemn oath to a common purpose — typically one adverse to a sovereign, lord, or established legal order. The term captures both the mechanism (the oath) and the result (the union or confederation formed by it).
Common Language
Modern common usage (Wiktionary): To conjure, in modern English, means to summon a spirit or supernatural force, or to call something to mind vividly; also, in older usage, to entreat solemnly.
Historical common usage (Webster's 1913): "To summon by a sacred name, or in a solemn manner; to implore earnestly; to bewitch or charm; to practice magic arts."
The gap between common and legal meaning is significant. In ordinary language, the word's dominant sense drifted toward conjuring spirits or magical invocation. In the historical legal context, *conjurare* had nothing to do with the supernatural — it was a precise term of political and criminal law describing a sworn confederation among persons, carrying overtones of sedition, conspiracy, or unlawful combination. A researcher encountering the term in a legal source should resist the modern common meaning entirely.
Common Confusion
*Conjurare* is closely related to but not identical with the English legal term **conspiracy**. Conspiracy, as it developed in common law, does not require a formal oath — an agreement or combination suffices. *Conjurare* specifically implies the oath as the constitutive act of the union. In medieval sources, the two concepts overlap heavily, but in later common law treatment, the oath element receded and conspiracy became the dominant operative term. Researchers should also distinguish *conjurare* from **coniuratio**, which is the noun form referring to the sworn confederation itself rather than the act of swearing.
Why It Matters in Research
*Conjurare* appears primarily in Latin legal texts, chronicles, and early medieval sources rather than in common law pleadings or modern statutory material. Researchers working in Anglo-Saxon law, Frankish law, or early English feudal materials will encounter it in contexts involving sworn guilds, conspiracies against the crown, and unlawful assemblies. The term carries a strongly negative valence in most legal sources — sworn combinations among subjects were treated with deep suspicion by sovereign authorities throughout the medieval period.
Several research traps exist. First, because the English word "conjure" has shifted so far from its legal Latin root, modern readers may misread passages in translated chronicles or legal summaries. Second, in ecclesiastical sources, *conjurare* sometimes appears in contexts that are not criminal at all — sworn brotherhoods or confraternities — so the negative legal connotation is not universal and depends heavily on context. Third, some early sources use *conjurare* and *coniuratio* interchangeably with terms for lawful oath-swearing assemblies (*jurationes*), requiring close reading to determine whether the source treats the act as licit or illicit.
For researchers tracing the ancestry of conspiracy doctrine, *conjurare* is an important antecedent term. The Ordinance of Conspirators (1293, England) and related early statutes addressed exactly the kind of sworn combination that *conjurare* describes, even as the formal Latin term receded from official legal usage.
Historical Dictionary Support
Burrill's Law Dictionary provides the core definition concisely: to swear together; to combine or confederate under oath. Burrill correctly identifies the Latin roots (*con-* and *jurare*) and captures both dimensions of the term — the act of joint swearing and the resulting confederation. The entry is brief and accurate as far as it goes but does not address the distinction between licit and illicit sworn combinations, the relationship to conspiracy doctrine, or the term's ecclesiastical usage. Researchers should treat Burrill's entry as a reliable starting point but not a sufficient guide to the term's full range in primary sources.
Other major historical legal dictionaries, including Black's early editions and Bouvier's, do not carry a dedicated entry for *conjurare*, reflecting its status as a classical Latin term that had largely exited common law pleading by the time those dictionaries were compiled. Its fuller treatment is found in Du Cange's *Glossarium Mediae et Infimae Latinitatis*, the standard reference for medieval Latin legal vocabulary, where the term's range across feudal, ecclesiastical, and criminal contexts is extensively documented.
Encyclopedia Cross-Reference
Law Mind Encyclopedia — Conspiracy
Law Mind Encyclopedia — Oath
Law Mind Encyclopedia — Unlawful Assembly