Definition
A term from Roman civil law designating a great-great-grandfather's brother — that is, the brother of one's abavus (great-great-grandfather). The relationship places the abpatruus at the outermost reaches of cognate kinship recognized in classical Roman law. Also called patruus maximus, reflecting his position as the most remote paternal uncle-equivalent in the ascending collateral line. Bracton and Fleta, writing in the common law tradition, rendered the term abpatruus magnus.
Common Confusion
ABPATRUUS is occasionally conflated with PATRUUS (a father's brother, i.e., a standard paternal uncle) or ABAVUS (the great-great-grandfather himself). The prefix ab- signals a generational remove: just as abavus is the great-great-grandfather, the abpatruus is that ancestor's sibling. Researchers working with Roman kinship tables should take care with the full term — patruus maximus appears in some sources as a synonym, and abpatruus magnus in the common law adaptations of Bracton and Fleta — but these all refer to the same relationship.
Why It Matters in Research
This term appears almost exclusively in civil law contexts concerning the rules of intestate succession and the degree of cognate relationship. In Roman law, the Institutes (3.6) and Digest (38.10) established a systematic table of kinship that English legal writers adopted when theorizing about inheritance at common law. Bracton's treatment (fol. 68b) and Fleta (lib. 6, c. 2, § 17) are the primary common law sources where abpatruus and abpatruus magnus appear, and researchers working with either text should recognize that these authors were translating Roman kinship categories into a common law framework — a translation that was often imprecise.
The practical significance of this specific term is narrow: by the time succession disputes reached the degree of relationship represented by the abpatruus, Roman law itself afforded only minimal claims, and common law courts rarely had occasion to apply the concept directly. The term is therefore more likely to surface in academic treatises, civil law glossaries, or the scholarly apparatus surrounding Bracton and Fleta than in case law or statute.
Researchers searching historical corpora should note variant spellings and renderings: abpatruus, ab-patruus, abpatruus magnus, and patruus maximus may all appear in reference to the same figure. Latin kinship terminology in historical English legal texts was not standardized, and errors of transcription are common — the discrepancy between "fol. 68b" (Burrill), "fol. 686" (Black's 1st ed.), and "fol. 680" (Black's 2nd ed.) for the Bracton citation illustrates this problem and should be verified against a critical edition of Bracton before relying on any particular folio reference.
Historical Dictionary Support
Black's Law Dictionary (both editions) and Burrill's Law Dictionary are in full agreement on the core definition: the great-great-grandfather's brother, identified as abavi frater. All three sources cite the same underlying Roman law authorities — the Institutes and the Digest — and note both the synonym patruus maximus and the Bracton/Fleta rendering abpatruus magnus. The minor folio discrepancies in the Bracton citation across editions are likely transcription errors and carry no substantive legal significance.
None of the historical dictionaries elaborate on the succession rules that gave the term practical legal content, nor do they explain the degree of kinship in the broader Roman table. Researchers needing the full doctrinal context must consult the Institutes and Digest directly, or a civil law treatise such as those of Domat or Pothier, which address collateral kinship more systematically.
Jurisdictional Note
This term belongs to Roman civil law and has no independent doctrine in modern common law jurisdictions. Its appearance in English legal literature is confined to scholarly reception of Roman law, primarily through Bracton and Fleta. Civil law jurisdictions (Louisiana, Quebec, Scotland, and European systems descending from Roman law) retain kinship-based succession frameworks, but modern codes use vernacular terminology rather than classical Latin designations.