Definition
In Roman civil law, comprivigni (singular: comprivignus or comprivigna) are the stepchildren of a married couple considered in relation to one another — that is, children each spouse brought to the marriage from a prior relationship, viewed as a class relative to each other. A husband's son by a former wife and a wife's daughter by a former husband are comprivigni to each other. The term does not describe the relationship between stepparent and stepchild (which is covered by privignus/privigna), but specifically the lateral relationship between co-resident stepchildren of different parentage united under one household.
The individual terms from which comprivigni derives are privignus (a stepson) and privigna (a stepdaughter). The prefix com- (Latin: together, with) signals the mutual, relational character of the designation.
Common Confusion
Comprivigni is sometimes conflated with privigni/privignae, but the distinction is precise and structural. Privigni/privignae describes stepchildren individually in relation to a stepparent. Comprivigni describes those same children in relation to each other — a lateral, peer relationship rather than a vertical, parental one. Researchers working with Roman family law texts should not treat these terms as interchangeable; they index different legal relationships and carry different consequences under Roman rules governing marriage impediments and inheritance.
Why It Matters in Research
This term appears almost exclusively in the context of Roman civil law, particularly discussions of family structure, marriage impediments, and the law of persons. Its practical relevance in historical legal research is narrow but precise.
Researchers working in Roman law sources should note that the Institutes of Justinian (Inst. 1, 10, 8) is the primary anchor text for this term. Historical legal dictionaries reproduce the definition nearly verbatim from that source, so the Institutes should be consulted directly when nuance matters.
The term is essentially a museum piece in modern common law jurisdictions, which developed their own vocabulary for blended-family relationships without borrowing this specific Latin framework. If you encounter comprivigni in an English-language legal text, you are almost certainly reading a civil law treatise, a comparative law work, or a passage discussing Roman law foundations of family law — not a practitioner document from a common law court.
One research trap: the Bouvier's entry retrieved under this term in some corpora appears to contain misfiled text about composition agreements between creditors — unrelated material that may have been bound or digitized alongside the correct entry. Do not rely on Bouvier's as a source for comprivigni without verifying that the retrieved text actually addresses Roman family law rather than creditor composition.
Cross-referencing within the corpus: comprivigni connects naturally to discussions of stepparent-stepchild relationships under Roman law, marriage prohibitions based on affinity, and the broader law of persons in civilian traditions. Researchers tracing how Roman family categories influenced later civil law systems (French, Spanish, Louisiana) may find the term appearing in comparative or historical sections of those bodies of law.
Historical Dictionary Support
The five historical dictionaries consulted show near-total agreement on this term, which is unusual and reflects the fact that all are drawing from a single authoritative source: Justinian's Institutes 1, 10, 8. Black's (both editions), Rapalje & Lawrence, and Burrill reproduce the definition in almost identical language. This convergence is informative — it tells the researcher that there is no meaningful doctrinal evolution to track across the dictionary shelf and no significant common law gloss on the Roman original.
Burrill adds the useful cross-references to Privignus and Privigna, which are the more frequently encountered terms in the same family. Rapalje & Lawrence appends a transition directly to the entry for Compurgator, confirming that comprivigni warranted only a short definitional stop in the American legal dictionary tradition — it was never a working term in common law practice.
What the historical dictionaries collectively miss: none addresses how this relationship category functioned in Roman inheritance law or in determining marriage impediments based on affinity, both of which are the contexts where the distinction between comprivigni and privigni/privignae would have had practical legal consequences. Researchers needing that doctrinal depth must go beyond the dictionary shelf to the Institutes directly and to civilian commentary.
Jurisdictional Note
Comprivigni as a legal category has no operative status in American common law or English law. It surfaces in Louisiana civil law scholarship and in comparative law contexts where Roman-law family structures are traced through their civilian descendants. In those contexts, French and Spanish equivalents may be used rather than the Latin.