Definition
A Latin civil law phrase meaning "from an intestate" or "in case of intestacy." Used to describe succession, inheritance, or heirship that arises when a person dies without a valid will. The phrase most commonly appears in two compound terms: *hereditas ab intestato* (an inheritance derived from an intestate) and *successio ab intestato* (succession to an intestate, or succession in case of intestacy). Both express the same underlying concept — that the transmission of property follows by operation of law, not by testamentary direction.
In the civil law tradition, *ab intestato* served as the foundational descriptor for the entire body of rules governing who takes property when there is no will. Blackstone identified it as the civil law counterpart to the common law rules governing descent and inheritance of real estate.
Why It Matters in Research
This is a term of art drawn from Roman and civil law, not a term native to the English common law tradition. Researchers working in early American or colonial legal materials — particularly those touching Louisiana, Quebec, Spanish land grants, or ecclesiastical courts — will encounter it frequently. In common law jurisdictions, the functional equivalent is "intestate succession" or simply "descent and distribution," and historical sources may use the terms interchangeably or in deliberate contrast.
The phrase appears in Justinian's Institutes and the Digest, so citations in historical legal dictionaries (including Burrill's and both editions of Black's) route directly to those Roman law sources. Researchers using 18th- or 19th-century conflict-of-laws materials should note that *ab intestato* succession was frequently the axis around which choice-of-law disputes turned — Story's *Conflict of Laws* addresses this directly, and the phrase anchors his analysis of which jurisdiction's rules govern movables versus immovables in cross-border estates.
Do not assume that sources citing *ab intestato* are describing common law intestacy rules. The civil law and common law systems diverged significantly on who qualifies as an heir, the treatment of collateral relatives, and the distinction between movable and immovable property. When the phrase appears in an English or American source, the author is typically either (1) drawing a civil law comparison, (2) writing in a jurisdiction with civil law roots, or (3) invoking Roman law doctrine for analytical purposes.
Historical Dictionary Support
Black's (1st ed.), Black's (2nd ed.), and Burrill's are in close agreement on the core definition, all tracing the phrase to Justinian's Institutes (2.9 and 3.2) and the Digest (38.6.1). The slight variation in citation form between editions is a transcription artifact, not a substantive difference.
Black's (1st ed.) adds the comparative note that *successio ab intestato* "answers to the descent or inheritance of real estate at common law," citing Blackstone's *Commentaries* (2 Bl. Comm. 490, 516) and Story's *Conflict of Laws* (§ 480). This comparative framing is useful: it signals that for 19th-century American lawyers, the phrase was a bridge concept connecting civil law and common law systems, not purely antiquarian terminology.
Burrill's adds the Greek equivalent (*ek diadochon*), which is useful for researchers tracing the concept through Byzantine or canon law sources. None of the three dictionaries discuss the modern statutory treatment of intestacy, which has largely displaced the civil law vocabulary in American practice. This is a gap researchers should note — the historical sources illuminate meaning but do not reflect the uniform acts (such as the Uniform Probate Code) that now govern intestate succession in most U.S. jurisdictions.
Jurisdictional Note
The phrase carries practical legal weight primarily in civil law jurisdictions and in historical materials from mixed legal systems. In Louisiana, Quebec, and other jurisdictions with civilian roots, *ab intestato* and its derivatives may appear in operative legal texts. In common law jurisdictions, the term is encountered almost exclusively in academic, comparative, or historical writing.