Definition
Concilium (Latin: council) is a term from old English and Roman law with two principal meanings:
1. A council or deliberative assembly. In English legal history, concilium referred to royal advisory and governing bodies, ranging from the king's privy council (concilium regis privatum) to the great council (magnum concilium regis), which was one of the earliest designations for what became Parliament.
2. An argument or day of argument in a cause. In procedural usage, concilium denoted a sitting of the court for the purpose of hearing argument, or a day granted to a defendant to present his case — functionally equivalent to an imparlance in that it involved a formal opportunity to be heard before the court.
Common Confusion
The two meanings of concilium are procedurally unrelated and should not be conflated. The council meaning is constitutional and historical; the argument-day meaning is procedural. Historical sources do not always clarify which sense is operative. Researchers encountering the term in old pleading records should look to procedural context; those encountering it in chronicles, constitutional histories, or royal records should presume the council meaning. The term is also easily confused with conclave, consistorium, and curia — overlapping Latin designations for royal or ecclesiastical assemblies that carried distinct legal weight in different periods.
Recognized Forms
/SUBTYPES
Concilium regis privatum — The king's privy council; also called concilium continuum (perpetual council) and concilium secretum regis (the king's secret council). This body exercised executive and quasi-judicial functions distinct from the broader deliberative assemblies.
Magnum concilium regis — The king's great council; the larger assembly of magnates and prelates that preceded and in some accounts gave rise to Parliament. Burrill cites this as one of the ancient names for the English Parliament itself.
Concilium (procedural) — A day or sitting allowed to a defendant to present argument; synonymous in practical effect with an imparlance in certain historical pleading contexts.
Why It Matters in Research
Researchers working in early English constitutional history will encounter concilium across a wide range of source types — legal chronicles, Year Books, plea rolls, and institutional histories — and the term's meaning will shift depending on the period and document type. The great council usage predates Parliament as a formal institution, and tracing the transition from magnum concilium to parliamentum is a live question in constitutional scholarship; sources in the Law Mind corpus that use concilium in a parliamentary sense may be using archaic or contested terminology by the standards of later centuries.
The procedural meaning — a day of argument or imparlance — appears in pleading records and early procedural texts and is easily overlooked when a researcher is focused on constitutional material. The overlap between the two senses within a single term means that indexing and keyword searches across the corpus may return mixed results requiring manual disambiguation.
Jurisdictional caution is warranted: concilium in Roman and civil law sources carries its own tradition, referring to provincial councils and advisory bodies under the empire, which is distinct from its English common law usage. Researchers using comparative or civilian sources alongside English materials should not assume continuity of meaning.
The term also anchors a cluster of related Latin designations — curia regis, parliamentum, consilium — that evolved in meaning across centuries. Understanding which body a medieval or early modern source is actually describing requires attention to the specific Latin term used, since English translators and later legal historians did not always distinguish these consistently.
Historical Dictionary Support
Bouvier offers only the bare translation: "a council." This is accurate but unhelpful for research purposes, providing no indication of the term's procedural dimension or its constitutional significance.
Black's is notably more complete, capturing both the council meaning and the procedural meaning — argument in a cause, a sitting for hearing argument, a day allowed to a defendant, an imparlance — but provides no historical context for how these usages relate to one another or to specific periods of legal development.
Burrill is the most substantive of the three, distinguishing the privy council (concilium regis privatum) from the great council (magnum concilium regis) and providing the important cross-reference to Parliament's origins. Burrill's citations to Crabb's History of English Law, Reeves' History of English Law, Coke's Reports, and Blackstone's Commentaries ground the term in its primary source tradition. Researchers should consult those works directly for the developmental arc of royal council institutions.
None of the three sources addresses the Roman or civilian usage of concilium, nor do they trace the transition from concilium to later English institutional terminology. The procedural meaning receives only brief treatment across all three, and no source explains how the argument-day usage connected to the doctrine of imparlance in practice.
Jurisdictional Note
The constitutional meanings of concilium are specific to English legal history and have no direct equivalent in American law. The procedural meaning — a day of argument — is likewise a relic of early English common law pleading practice and does not appear as operative terminology in modern American or English courts.