Definition
Arrestatio is a Latin legal term from old English law meaning an arrest or arrestment — the formal seizure or detention of a person or property by legal authority. The term appears in medieval and early modern legal records and pleadings as the Latin equivalent of the English "arrest." A specialized compound form, arrestatio navium, denotes the arrest or detention of ships, a procedure with distinct applications in maritime and admiralty practice.
Common Confusion
Arrestatio should not be confused with the modern procedural concept of arrest as defined by contemporary criminal procedure law. The Latin term encompasses both personal arrest (seizure of a person) and in rem arrest (seizure of property, particularly vessels), whereas modern common law usage has largely confined "arrest" to the detention of persons. A researcher encountering arrestatio navium in historical sources should recognize this as an admiralty or maritime procedure, not a criminal law action.
Why It Matters in Research
Arrestatio is a navigational term for historical legal sources, not a substantive doctrine with continuing independent life. Researchers are most likely to encounter it in:
Medieval pleading records and Year Books, where Latin forms dominated formal legal writing. The term signals that the surrounding document likely predates the systematic shift to English in legal proceedings.
Admiralty and maritime sources. The phrase arrestatio navium appears in maritime law treatises dealing with the seizure of vessels — a procedure that persisted in admiralty courts well after Latin fell out of common use in other courts. Researchers working on ship seizures, prize law, or maritime liens should be alert to this form.
Transitional-era documents. During the period when English courts were shifting between Latin, Law French, and English, the same underlying procedure might appear under different names in different sources. Recognizing arrestatio as equivalent to "arrest" (and, in maritime contexts, to what later became the in rem arrest of a vessel) prevents misidentification of the legal action being recorded.
The practical trap is treating the term as having a technical meaning distinct from "arrest." It does not. It is the Latin rendering of the same concept, and the substantive law governing it is found under the broader entry for arrest and, for maritime matters, under admiralty procedure.
Historical Dictionary Support
The historical dictionaries are consistent but thin. All four sources — Black's (both editions), Rapalje & Lawrence, and Burrill — identify arrestatio simply as the Latin equivalent of "arrest" in old English law, directing the reader to that entry rather than developing independent doctrine.
Burrill is the most useful of the group, adding the specific compound arrestatio navium and citing two sources: Townsend's Pleadings (pl. 53) and Loccenius, De Jure Maritimo (lib. 3, c. 5). The Loccenius citation is significant — Johannes Loccenius's De Jure Maritimo et Navali (published in the mid-seventeenth century) was a recognized authority on European maritime law, and its appearance in Burrill signals that arrestatio navium carried weight in the continental and admiralty law traditions, not merely in English common law pleading.
Black's entries in both editions are fragmentary as reproduced here, offering little beyond the cross-reference. Rapalje & Lawrence adds nothing beyond what Black's provides. No historical dictionary entry develops the term's procedural content or traces its evolution — researchers must follow the cross-references to "arrest" and to admiralty sources for that substance.
Jurisdictional Note
Arrestatio as a live term belongs entirely to historical legal sources. Its maritime variant, arrestatio navium, connects to admiralty jurisdictions that operated under distinct procedural rules from common law courts, and researchers should be aware that admiralty practice varied between English, Scottish, and continental European sources even when the Latin terminology appeared uniform.