Definition
Unde vi (Latin: "wherefrom by force") is a Roman civil law term designating a specific type of praetorian interdict used to restore possession of immovable property — land or structures — to a person who had been forcibly dispossessed. The interdict unde vi directed the person who had used force to vacate and return the property to the dispossessed possessor. It operated as a possessory remedy, not a proprietary one: the focus was on the wrongful use of force, not on who held superior title to the property.
Under classical Roman procedure, the interdict unde vi was available against the person who committed the forcible ejection or, in some formulations, against those who aided in it. The remedy was grounded in the praetor's power to suppress self-help and preserve public order, independent of any underlying question of ownership.
Common Confusion
Unde vi is sometimes conflated with the interdict uti possidetis, the other major Roman possessory interdict. The distinction matters: uti possidetis protected a possessor against ongoing disturbance or threatened dispossession and applied to both movable and immovable property in certain formulations, while unde vi addressed completed forcible ejection from immovables specifically. A researcher encountering either term in a civil law source should confirm which remedy is meant before drawing analogies to modern dispossession actions.
Unde vi should also be distinguished from the interdict unde vi armata, a variant specifically addressing ejection accomplished by armed force or a mob. Some sources treat armata as a separate interdict; others treat it as an aggravated form of unde vi with a longer limitation period and fewer defenses available to the ejector.
Recognized Forms
/SUBTYPES
Interdict unde vi cotidiana (ordinary unde vi): Applied to forcible ejection by an individual or small group without weapons. The dispossessed party generally had to bring the action within one year.
Interdict unde vi armata (armed unde vi): Applied where the ejection was accomplished by armed men or organized force. The limitation period was extended and the defense that the complainant was a vicious possessor (vi, clam, aut precario) was typically unavailable, making recovery easier for the ejected party.
Why It Matters in Research
Unde vi appears primarily in Roman law treatises, institutional works, and civil law jurisdictions drawing on the Roman tradition. Researchers working in historical common law sources will rarely encounter it directly, but it is an essential reference point for understanding the intellectual lineage of possessory remedies — including ejectment and forcible entry and detainer actions — which English common law developed partly in response to the same problem (forcible self-help dispossession) that unde vi addressed.
For researchers using Law Mind sources, the term is most likely to surface in:
Treatises on Roman or civil law procedure. Works by Heineccius, Mackeldey, and similar institutional writers are the primary authorities Burrill cites, and those texts treat unde vi within the broader interdict system.
Comparative law discussions. Nineteenth-century American and English legal writers sometimes invoked unde vi when arguing about the scope or rationale of ejectment and related remedies.
Scottish, Louisiana, Quebec, and South African law materials. Jurisdictions with mixed common law/civil law traditions more directly inherited Roman possessory concepts, and unde vi may appear in case law or commentary with continuing doctrinal relevance rather than merely historical interest.
The one-year limitation on ordinary unde vi and the distinction between armed and unarmed force are details that recur across sources and can affect how a researcher interprets a historical argument about the scope of possessory protection.
Historical Dictionary Support
Burrill's entry is accurate and tightly written. It correctly identifies unde vi as a species of interdict, limits it to immovables, and grounds recovery in forcible ejection. The citations to Justinian's Institutes (4.15.6), Heineccius's Elementa Juris Civilis, and Mackeldey's treatise are the standard reference chain for this topic in Anglo-American legal literature of the nineteenth century.
What Burrill does not capture — appropriately for a dictionary entry — is the procedural mechanics: the interdict was not a judgment but a praetorian order, and the possessory question it resolved did not bind a subsequent petitory (ownership) action. A party could win under unde vi and still lose title in a later proceeding. This distinction between possessory and proprietary relief is foundational to understanding how the remedy worked and why it was influential as a model.
Burrill also omits the armed/unarmed distinction. Researchers who need the full typology should go directly to Heineccius or Mackeldey rather than relying on the dictionary entry alone.
Jurisdictional Note
Unde vi as a functioning remedy is specific to civil law systems. In common law jurisdictions, analogous protection against forcible dispossession developed through forcible entry and detainer statutes and the action of ejectment, neither of which is historically or formally derived from unde vi, though comparative legal scholars have noted the structural parallel. In mixed jurisdictions such as Louisiana and Scotland, Roman possessory concepts have had more direct doctrinal influence.