Definition
In Roman law, *incestuosi* (singular: *incestuosus*) refers to children born of incestuous unions — that is, offspring conceived through sexual relationships between persons within the degrees of kinship or affinity that rendered marriage between them unlawful. The term is a Latin substantive derived from the adjective meaning "incestuous" and is used in legal contexts specifically to describe the status and legal disabilities attached to such children, rather than the act of incest itself.
Under Roman law, incestuosi occupied a category of persons with diminished legal standing. They were distinguished from legitimate children, illegitimate children (spurii), and natural children, each category carrying its own set of inheritance rights and civil disabilities. The incestuosi were among the most disadvantaged in terms of succession and recognition under Roman civil law.
Why It Matters in Research
This term appears almost exclusively in research touching on Roman law, civil law systems derived from Roman foundations, or comparative legal history. Researchers encountering *incestuosi* in historical sources should be alert to the following:
First, the term describes a legal status category, not merely a moral or factual description. Roman law's elaborate taxonomy of birth status — legitimate, illegitimate, natural, *spurii*, *vulgo quaesiti*, *incestuosi* — has no direct modern common law counterpart, and conflating these categories distorts historical analysis.
Second, sources discussing inheritance rights, intestate succession, or the capacity to take under a will in Roman or civil law systems may use *incestuosi* without extensive definition, assuming the reader's familiarity. The practical consequence in those sources is almost always a complete or near-complete bar to inheritance and to recognition of paternal lineage.
Third, researchers working in Louisiana, Quebec, or other mixed jurisdictions with civil law heritage may find remnants of Roman-derived status categories in early legal materials, though modern statutes in these jurisdictions have long since abandoned formal distinctions of this type.
Fourth, when Bouvier's entry on *incestuosi* is located in a digitized corpus, researchers should note its placement immediately adjacent to the entry for INCH — an artifact of alphabetical organization, not conceptual connection. Cross-referencing the surrounding entries for context will not yield relevant material.
Historical Dictionary Support
Bouvier's Law Dictionary provides a minimal entry: "Those offspring incestuously begotten," citing Mackeldey's Roman Law at section 143. This is a functional but bare definition that conveys the category without explaining its legal consequences. Bouvier's brevity here is characteristic of his treatment of Roman law terms that he considered sufficiently covered by civilian treatises; researchers should not mistake the short entry for a complete account.
Mackeldey's *Compendium of Modern Civil Law* (the work Bouvier cites as "Mack. Rom. L.") provides the fuller context: Roman law grouped the incestuosi with other categories of persons born outside lawful marriage but treated them more harshly than ordinary illegitimates because the union producing them was not merely irregular but affirmatively prohibited. The incestuosi generally could not claim the father's name, could not inherit on intestacy from the father, and were excluded from benefits that even acknowledged illegitimate children might receive.
No significant divergence exists among historical legal dictionaries on the core meaning — the term was stable in civilian usage. What historical sources largely omit is any discussion of the term's trajectory: it becomes a historical curiosity in common law jurisdictions and fades from active legal use even in civil law systems as nineteenth- and twentieth-century codifications moved away from formal birth-status disabilities.
Jurisdictional Note
*Incestuosi* as an operative legal category belongs to Roman and classical civil law. Modern jurisdictions, whether common law or civil law, have generally abolished formal legal distinctions based on the circumstances of birth. Researchers should treat the term as a historical Roman law classification rather than as a living legal category in any current jurisdiction.