Definition
A Latin term used in civil law and historical English law to denote a line of descent — specifically, a series of persons tracing their lineage from a common ancestor. The linea was the structural unit for computing degrees of kinship, governing inheritance rights, and determining succession to estates under both Roman-derived civil law and old English common law.
The term carries two principal orientations:
1. Linea recta (direct line): The vertical line of descent, connecting persons who stand in a direct relationship of ancestor and descendant — grandparent to parent to child, ascending or descending. In computing degrees of kindred, the linea recta counts the generations separating two persons in this direct chain.
2. Linea transversalis (also called linea obliqua or linea sata, in older usage): The collateral line, connecting persons who share a common ancestor but do not descend directly from one another — siblings, cousins, uncles, and nephews. Succession rules under civil law treated this line differently from the direct line, often imposing stricter limits on collateral inheritance.
Within the linea recta, the line could be ascending (linea ascendens — from the individual upward toward parents, grandparents, great-grandparents) or descending (linea descendens — from the individual downward to children, grandchildren, and so on). Burrill notes explicitly that the linea was ascendens as well as descendens, a point occasionally overlooked in condensed treatments of the term.
Common Language
Modern common usage (Wiktionary): In contemporary general use, linea refers either to a long surface marking on a planet or moon, or to a traditional Spanish unit of length roughly equivalent to 1.9 mm.
Historical common usage: The term does not appear in Webster's 1913 as a primary English entry; it remained largely a Latin and civil-law technical term throughout the historical period covered by the reference shelf.
Editorial note: The gap here is categorical rather than subtle. Common usage of linea — astronomical surface features, a unit of measurement — bears no relationship to the legal term. Encountering linea in a historical legal source almost certainly signals the law of descent and kinship, not geography or mensuration.
Recognized Forms
/SUBTYPES
Linea recta: The direct or vertical line of descent, connecting ancestors and descendants.
Linea transversalis: The collateral or oblique line, connecting persons sharing a common ancestor but not in direct descent. Also called linea obliqua in some civil law sources.
Linea sata: An older variant term for the oblique or collateral line; Black's 2nd edition treats this as a predecessor to the more standardized linea transversalis. The terminological variation matters when reading older authorities.
Linea ascendens / Linea descendens: Subdivisions of the linea recta, distinguishing movement upward toward ancestors from movement downward toward descendants.
Why It Matters in Research
Researchers will encounter linea almost exclusively in historical sources dealing with inheritance, intestate succession, and the computation of degrees of kindred under civil law or its English analogues. The term is not active in modern American statutory drafting, where plain-language equivalents (line of descent, collateral heirs, direct descendants) have largely displaced Latin.
The principal research trap is terminological inconsistency across historical sources. The oblique or collateral line appears variously as linea transversalis, linea obliqua, and linea sata depending on the era and jurisdiction of the source. A researcher moving between Roman law texts, canon law materials, and old English authorities should not assume these terms are perfectly synonymous in context — the underlying doctrine may be consistent while the vocabulary shifts.
The civil law degree-counting method (counting up to the common ancestor, then down to the other person) differs from the canon law method used in some ecclesiastical and marriage-prohibition contexts. When a historical source invokes linea recta or linea transversalis in the context of prohibited degrees of marriage rather than inheritance, the applicable counting method may differ. Failure to track which system a source uses produces errors in interpreting the authority.
Burrill's treatment is the most substantive of the shelf sources on this term and provides the most useful structural framework, including the reference to Heineccius's civil law elements — a foundational continental source that shaped how English-trained lawyers understood Roman family law.
Historical Dictionary Support
The shelf sources are in broad agreement that linea denotes a line of descent from a common ancestor, and all three direct the reader toward related entries (Black's both editions: "See LINE"). Burrill provides the most granular treatment, defining the term as "a series of persons descending from a common stock" and citing Heineccius, Hale's Analysis of the Law, and Fleta — sources that situate the term firmly within both civil law and medieval English legal learning.
Black's 2nd edition is more useful than the 1st on this entry because it explicitly distinguishes linea sata from linea transversalis, flagging the terminological evolution that the 1st edition collapses. Neither Black's edition discusses the ascending/descending subdivision of the linea recta with any depth; Burrill's note that the linea was "ascendens as well as descendens" fills a gap the Black's entries leave open.
What the historical dictionaries collectively miss is any discussion of how the civil law doctrine of linea was absorbed — and sometimes altered — when received into English ecclesiastical courts and later into equity practice governing inheritance. Researchers working in those domains will need to supplement dictionary sources with treatise material.
Jurisdictional Note
The term is native to Roman civil law and appears in historical English sources primarily through the influence of civil law on ecclesiastical courts, equity, and the law of intestate succession. Modern American and English statutes on descent have replaced Latin terminology, but linea and its subtypes remain essential for reading pre-modern primary sources and authorities drawing on civil law tradition.