Definition
In Roman and civil law, an arrogator is a person who adopts another by the process of arrogation — a formal mode of adoption in which a person who is legally independent (sui juris) is taken into the family of another. The arrogator is the adopting party: the one who receives the adoptee into his household, acquires paternal power (patria potestas) over that person, and assumes legal responsibility for the adoptee's debts and obligations.
Arrogation was distinguished from ordinary adoption (adoptio) in that its subject was not a child under parental authority but a legally autonomous adult. Because the arrogation extinguished one independent legal personality and absorbed it into another family, it required a higher level of public authorization than ordinary adoption — originally by the comitia calata (a form of Roman assembly), and in the later imperial period by imperial rescript.
Common Confusion
ARROGATOR vs. ADOPTIVE PARENT (ADOPTANS): The arrogator is specifically the party in an arrogation, not in ordinary adoptio. The distinction matters in civil law sources because the two procedures had different requirements, different effects on property, and different rules regarding who could serve as the adopting party. In research, conflating arrogation with general adoption will cause sources to appear contradictory, since the rules governing each diverged considerably across different periods of Roman law.
Why It Matters in Research
This term appears almost exclusively in civil law and Roman law contexts. Researchers will encounter it in treatises and digests dealing with family law, inheritance, and succession under Roman law, canon law, and the civilian tradition in continental Europe. It has no operative meaning in modern common law jurisdictions.
The primary research trap is anachronism: modern notions of adoption — focused on child welfare, statutory procedure, and the interests of minors — bear little resemblance to arrogation, which was fundamentally a transaction between adult legal persons with significant consequences for property, sacral obligations, and family continuity. Reading arrogation through a modern adoption lens will distort the analysis.
A second trap involves the period of the source. In the Republic and early Empire, arrogation required approval by public assembly. By Justinian's time, the imperial rescript procedure referenced in Burrill's citation (Institutes 3.11.1–3) had replaced this. Sources from different periods will describe different procedural requirements, and both descriptions will be technically accurate for their time.
Researchers following chains of succession or inheritance in civil law materials should note that arrogation transferred the arrogated person's property to the arrogator's family and could extinguish existing obligations. This makes the arrogator a legally significant actor not just in family law but in property and succession questions.
Historical Dictionary Support
Burrill's entry is brief but precise: it identifies the arrogator as the adopting party in arrogation, specifies the civil law context, and anchors the definition to the Institutes of Justinian (3.11.1–3). The citation is reliable and the definition accurate as far as it goes.
What Burrill does not supply — and what researchers should seek in fuller civil law authorities — is the substantive framework: the requirement that the arrogator be capable of having children (and thus capable of patria potestas), the prohibition on arrogation that would leave the arrogator's existing family without an heir, and the protections Justinian introduced for arrogated persons against disinheritance. Burrill's entry functions as a locator, not a complete account.
Standard Roman law treatises in the civilian tradition, including Gaius's Institutes and the Digest, provide the fuller picture. Researchers using only Burrill risk underestimating the legal weight of the arrogation transaction.
Jurisdictional Note
The arrogator as a legal category has no direct counterpart in modern common law. The term survives in civil law scholarship, canon law commentary, and historical legal analysis. Louisiana, Quebec, and other mixed or civilian jurisdictions may preserve civilian adoption terminology in older sources, but modern statutory adoption has superseded arrogation as a live legal concept everywhere.
Encyclopedia Cross-Reference
Law Mind Encyclopedia — Arrogation
Law Mind Encyclopedia — Roman Family Law
Law Mind Encyclopedia — Patria Potestas