Definition
Latin: "hand." In legal usage, manus carries two distinct meanings depending on context:
1. Roman and Civil Law. Manus denoted power, control, or authority—particularly the legal dominion a husband acquired over his wife upon marriage under the older Roman form known as marriage cum manu. This power encompassed the right of physical coercion and was used interchangeably with potestas. Under manus, a wife passed out of her own family's legal control and into that of her husband (or his paterfamilias), surrendering independent legal personality. The institution declined during the later Republic and had largely disappeared by the classical period.
2. Old English Law. Manus signified an oath or, more specifically, the person taking an oath—a compurgator. To "swear by twelve hands" (jurare duodecima manu) meant to swear with eleven compurgators supporting the oath of a twelfth, the principal swearer. This usage reflects the procedural role of oath-taking and compurgation in early common law dispute resolution.
Common Language
Modern common usage (Wiktionary): A surname of Irish origin; no general English meaning in current use.
Historical common usage (Webster's 1913): The distal segment of the forelimb, including the carpus and forefoot or hand—an anatomical term used in zoology.
The common English word and the legal term share Latin ancestry (both derive from manus, "hand") but diverge sharply in application. Neither the anatomical nor the surname usage signals anything about the legal concept of authority or oath-taking. A researcher encountering manus in a legal or historical text should not allow the literal meaning of "hand" to obscure what is almost always a technical reference to either Roman marital authority or English compurgatory procedure.
Recognized Forms
/SUBTYPES
Manus mortua ("dead hand"): The Latin equivalent of mortmain—property held in perpetuity by an ecclesiastical or corporate body, beyond the reach of ordinary alienation or feudal incident. Noted in Black's (2nd Ed.) with reference to Spelman.
Manu brevi ("with short hand"): Briefly; summarily. Used in pleading and procedural contexts to indicate direct or abbreviated action.
Manu forti ("with strong hand"): Forcibly; by force. Appears in common law pleading, particularly in actions for forcible entry or disseisin.
Molliter manus imposuit ("he laid hands upon him lightly"): A plea in justification of an assault or trespass, asserting that only minimal force was used—for example, to preserve the peace, prevent a crime, or protect one's dwelling. A recognized defensive plea in early common law practice.
Why It Matters in Research
Manus is a gateway term that opens into several distinct areas of the Law Mind corpus, and conflating its meanings across contexts is a genuine research hazard.
In Roman law materials, manus is inseparable from the structure of the Roman family and the law of persons. Researchers working with civil law sources, continental treatises, or early American works drawing on Roman foundations will encounter manus primarily in its first sense—authority over persons, especially wives. The decline of manus as an institution in Roman law is itself legally significant: the shift from marriage cum manu to marriage sine manu altered inheritance patterns, dowry law, and the wife's legal capacity. Historical sources written at different points may assume different baseline conditions.
In early English law sources, manus shifts entirely to oath procedure. Compurgation—where a defendant's oath was supported by oath-helpers swearing to his credibility—was a primary mode of proof before the rise of the jury. Understanding manus in this sense is prerequisite to reading plea rolls, procedural treatises, and accounts of trial by wager of law. The phrase jurare duodecima manu (to swear by twelve hands) appears in Burrill and reflects an older numerical convention for compurgation that varied by court and status.
Manus mortua connects to the separate and extensively documented body of mortmain law. Researchers should follow that thread under MORTMAIN rather than under MANUS.
The adverbial phrases—manu brevi, manu forti—appear most often in pleadings and writs. Manu forti in particular is associated with forcible entry actions and appears in older English and American form books. Molliter manus imposuit is a plea formula worth recognizing in its own right.
Historical Dictionary Support
The four source dictionaries agree on the core Roman and English meanings but vary in depth. Black's (both editions) gives the cleanest summary: the civil law sense of power and authority (synonymous with potestas) and the English sense of oath or compurgator. Anderson's is the most practically useful for the adverbial forms, providing manu brevi, manu forti, and the full formula for molliter manus imposuit. Burrill adds the most on the compurgation context, connecting manus to the mechanics of oath-swearing on the Gospels and the manumission relationship—noting that so long as a person was in servitude, they were subject to the "hand and power" of their master (manui et potestati suppositus est), and that manumission (literally, "sending from the hand") released them. This etymology illuminates why manus carried such broad connotations of dominion.
Black's (2nd Ed.) is the only source among the four to flag manus mortua explicitly, attributing the usage to Spelman's Glossarium. Spelman remains the primary historical authority for Anglo-Latin legal terms of this period.
What the historical dictionaries do not do is connect manus systematically to the Roman law of marriage or to the procedural history of compurgation. Researchers needing that context should move to the encyclopedia corpus.
Jurisdictional Note
Manus as a substantive legal institution (Roman marital authority, compurgation) has no living jurisdictional application in common law systems. Its relevance is historical and interpretive. Manu forti retains occasional appearance in older American property and criminal pleading contexts drawn from English common law forms.