Definition
TAV is a historical term appearing in the context of ancient Irish customary law, specifically as a variant designation connected to the rules of inheritance and succession governing certain classes of land and title in early Ireland. As recorded in Burrill, the term appears in connection with the mode of descent by which castles, manors, lands, and tenements passed to the eldest and most worthy man of the blood and race of the deceased — a system closely associated with the doctrine of tanistry.
The term itself functions less as a freestanding legal concept and more as a label attached to a particular customary inheritance rule in pre-Norman and early colonial Irish law. Its precise technical content is inseparable from the broader framework of Gaelic succession customs, in which inheritance did not follow the strict primogeniture rules of English common law but instead favored the most capable or senior male within the kin group.
Common Language
Modern common usage (Wiktionary): An alternative form of "taw," the final letter of the Hebrew and Semitic alphabets.
Historical common usage: Not independently attested in Webster's 1913 in this form; the root "taw" appears as a letter designation with no legal content.
The gap here is complete. The common-language "tav" carries no legal meaning whatsoever — it is a Semitic letter designation. Its appearance in legal sources is entirely confined to a specialized term of Irish customary law, likely representing a Gaelic or Hiberno-Latin word adapted into English-language legal writing. Researchers encountering "tav" in a legal manuscript context should not assume alphabetic or notarial significance.
Why It Matters in Research
This term will appear rarely and only in historical sources dealing with Irish customary land law, colonial-era Irish legal records, or antiquarian legal treatises. Researchers should be alert to several navigational challenges:
First, the term is not systematically indexed in standard English legal dictionaries. Burrill's entry is one of the few English-language legal dictionary treatments, and even there it appears mid-passage without a standalone headword entry, embedded in discussion of related Irish customs. Researchers working in digitized corpora should search variant spellings — tav, taw, and potentially Gaelic cognates — to avoid missing relevant passages.
Second, the underlying concept it represents — succession to the worthiest male of the blood rather than the eldest son — was a central point of controversy in English colonial administration of Ireland. Cases and treatises debating the validity of Irish customary law, including tanistry and gavelkind, frequently invoked these descent rules. The landmark early seventeenth-century case on the custom of tanistry (reported by Sir John Davies) is the primary common-law treatment of this framework and is cited in Burrill's own passage.
Third, researchers should not conflate tav-type succession with English gavelkind (partible inheritance among all sons), which operated on entirely different principles. The confusion is easy to make because both systems rejected primogeniture, but the outcomes differed sharply.
Fourth, in the Law Mind corpus, passages discussing Irish land tenure, colonial land grants, or the suppression of Gaelic customs are the most likely locations for this term. Cross-referencing with tanistry will almost always be necessary.
Historical Dictionary Support
Burrill's treatment is brief and derivative, relying on Sir John Davies' Irish Reports and Ware's Antiquitates Hiberniae, as well as Cowell's legal dictionary. Burrill does not define tav independently but situates it within the description of the mode of descent applicable to castles, manors, lands, and tenements in Ireland under Gaelic custom. The definition that emerges from context is functional rather than formal: tav designates the rule or status associated with succession to the worthiest male of the blood.
No independent treatment of tav as a discrete term appears in the other major historical English law dictionaries (Tomlin, Jacob, Bouvier, Black's early editions). This absence is itself informative — the term was recognized as a term of art specific to Irish antiquarian and colonial legal discourse rather than as a term of general English law. Researchers relying solely on standard English-law dictionaries would miss it entirely.
Ware's Antiquitates Hiberniae (1654) and Davies' Reports are the primary primary-source treatments underlying all later dictionary references to this concept. Any serious research into tav should engage those sources directly rather than relying on dictionary summaries.
Jurisdictional Note
This term is specific to Irish law, primarily the Gaelic customary law that English colonial administration encountered, contested, and ultimately sought to extinguish in Ireland during the sixteenth and seventeenth centuries. It has no recognized application in English, Scottish, Welsh, or American legal systems.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia — Gavelkind; Tanistry; Irish Land Tenure