Definition
Exhaeredatio (also spelled exhæredatio) is a term from Roman and civil law referring to the formal act of disinheritance — the deliberate exclusion of a person, typically a natural heir, from an inheritance to which they would otherwise be entitled by law or family expectation. In its civil law sense, the term describes a testator's express act of cutting off a legal heir, particularly a child, from succession. In the common law tradition, the term carried the related but distinct meaning of disherison: an injury inflicted upon a person who holds an expectant interest in property, such as a remainderman or reversioner, by depriving them of their anticipated inheritance.
The term is primarily encountered in historical legal sources and is not in active modern use in English-language jurisdictions. It survives in legal scholarship and in older treatises engaging with Roman law, civil law, and early common law inheritance doctrine.
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Common Confusion
Exhaeredatio and disherison are related but not identical. Exhaeredatio in its strict civil law sense refers to the testator's affirmative act of expressly excluding an heir in a will — a procedural requirement in Roman law that had to be done explicitly or the will could be invalidated. Disherison in the common law sense is broader and can refer to any deprivation of an expected inheritance, including harm done by a third party to a remainderman or reversioner, not merely a testator's deliberate choice. Researchers should not treat the two terms as interchangeable across legal traditions.
Exhaeredatio should also be distinguished from intestacy, which is the absence of a valid will. Disinheritance presupposes a testamentary act; a person is not exhaeredated merely because a testator died without naming them.
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Why It Matters in Research
This term is a structural pattern case of historical evolution. Its meaning shifts depending on which legal tradition — Roman civil law or English common law — the source is engaging, and researchers who encounter it in historical texts must identify that context before interpreting it.
In Roman law sources and civil law treatises, exhaeredatio is a technical term of considerable consequence. Roman law, particularly as codified in Justinian's Institutes (Inst. 2.13), required that a testator either expressly institute or expressly disinherit certain heirs — particularly children in the paternal line. Failure to do either could render the will defective. The act of exhaeredatio therefore had formal procedural requirements; it was not sufficient to simply omit an heir. Researchers working in Roman law, canon law inheritance doctrine, or civilian jurisdictions will encounter this procedural dimension.
In English common law sources, including Bracton (fol. 383, cited by Burrill), the term appears in a different register. There it describes harm done to a person with an expectant property interest — a remainderman or reversioner — who is wrongfully deprived of what they stood to inherit. This usage is closer to what modern lawyers might call tortious interference with an inheritance expectancy, though that framing is anachronistic.
The dual usage creates a research trap: the same Latin term, appearing in two different bodies of source material, points toward two different doctrinal problems. A citation to exhaeredatio in a Romanist treatise and a citation in a Bractonian common law text are not discussing the same legal phenomenon.
Researchers should also be attentive to spelling variation. Both exhaeredatio and exhæredatio appear in historical sources, and the ligature æ may cause search failures in digitized text repositories. Search for both forms.
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Historical Dictionary Support
Burrill's Law Dictionary provides the most direct source-dictionary treatment available. Burrill distinguishes the civil law and common law senses explicitly, which is valuable, though the entries are brief. He cites Justinian's Institutes (Inst. 2.23) and Bracton (fol. 383) for the respective traditions, and references Heineccius's Elementa Juris Civilis (lib. 2, tit. 13, § 528) for the civil law definition of exhaeredatio as "an exclusion from the lawful inheritance." The Heineccius citation points researchers toward a systematic civilian treatment of the concept.
Burrill's entry for the companion term EXHAERES — a person who has been disinherited, literally "one outside the inheritance" (from ex, privative, and haeres, heir) — provides the logical counterpart and is worth consulting alongside exhaeredatio for completeness.
What the historical dictionaries do not supply is any treatment of the formal procedural requirements for valid exhaeredatio under Roman law — the distinction between express and implied disinheritance, the rules governing sons versus daughters, and the remedy of the querela inofficiosi testamenti (the complaint against an undutiful will) available to heirs who believed they had been wrongfully excluded. For that doctrinal depth, researchers must move beyond dictionary sources to Romanist treatises and the Institutes themselves.
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Jurisdictional Note
Exhaeredatio as a term of art is not operative in modern common law jurisdictions, which address disinheritance through will construction, forced heirship statutes (where applicable), and elective share doctrine. It remains relevant in civil law jurisdictions with forced heirship regimes that trace lineage to Roman law, and in academic legal history across both traditions.
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