Definition
Mutatio nominis (Latin: "change of name") is a civil law term referring to the formal alteration of a person's name under Roman law. The concept addressed the legal consequences and permissibility of name changes, including whether a change of name could be used to evade legal obligations, avoid judgment, or obscure identity for fraudulent purposes. In its classical Roman law context, the term appears in connection with prohibitions against using name changes as a mechanism to defeat legal process or circumvent the effects of infamy (infamia).
Why It Matters in Research
Researchers encountering this term in historical sources should be aware of several navigational considerations.
First, the term is exclusively a civil law (Roman law) concept and will appear primarily in sources dealing with Roman or civilian legal systems — continental European legal traditions, ecclesiastical law, and early American treatises that borrowed from civilian doctrine. It will not appear in common law sources as an operative legal term.
Second, the Codex reference (Cod. 9, 25) points to Book IX, Title 25 of the Justinian Code, which addressed the use of name changes to escape the legal consequences of infamy or condemnation. Researchers working in primary civilian sources should consult this title directly. The citation is consistent across all three source dictionaries and provides a reliable anchor into the Roman primary material.
Third, this term should not be confused with modern statutory name change procedures, which are creatures of domestic legislation and bear no doctrinal connection to mutatio nominis beyond the surface-level subject matter. American and English courts developed name change law independently of the Roman civil law tradition.
Fourth, the term may surface in treatises on the law of persons, conflict of laws, or ecclesiastical law when authors are tracing the historical pedigree of name-related legal rules. Its appearance in a text signals the author is working in a civilian or mixed-jurisdiction tradition.
Historical Dictionary Support
All three source dictionaries — Black's (first and second editions) and Burrill's — provide identical substantive entries: the Latin translation ("change of name"), the civil law provenance, and the citation to Cod. 9, 25. The agreement across sources is complete, which reflects the term's narrow and settled meaning rather than any live doctrinal debate.
The Burrill's entry appears to contain a corrupted passage in the surviving text ("In the loan were such articles as might be weighed, counted or measured, quæ pondere..."), which suggests a typesetting or transcription error in the digitized source — that language belongs to a different entry, likely concerning mutuum (the Roman law loan of fungible goods). Researchers relying on digitized versions of Burrill's should be alert to this artifact; it does not reflect any genuine association between mutatio nominis and the law of fungible loans.
None of the historical dictionaries elaborate on the substantive legal rules contained in Cod. 9, 25, nor do they address how civilian jurists applied the doctrine in practice. For substantive treatment, researchers should turn to commentaries on the Justinian Code or encyclopedic works in the continental tradition.
Jurisdictional Note
Mutatio nominis is a Roman civil law term with no operative function in common law jurisdictions. In mixed-law systems (Louisiana, Quebec, South Africa, Scotland), it may appear in historical or comparative legal writing but does not constitute an independent cause of action or procedural mechanism. Modern name change law in all major jurisdictions is statutory.