Definition
De intrusione (Latin: "of intrusion") is a common law writ directed against a stranger who unlawfully entered land after the death of a tenant, thereby injuring the reversioner's right to possession. The writ was a remedy available to the holder of the reversion — typically the feudal lord or grantor — when an unauthorized third party seized the land before the reversioner could take possession following the tenant's death.
The wrong it addressed was distinct from ordinary trespass. The intruder had no colorable claim to the land; the injury lay not in a disputed title but in the wrongful interruption of the reversioner's expectant right at the precise moment it should have ripened into actual possession.
Why It Matters in Research
De intrusione is an archival term. Researchers will encounter it almost exclusively in older English common law materials — Year Books, Registers of Original Writs, and treatises on real property actions — rather than in American case law. Its practical use died with the feudal tenure system and the abolition of the forms of action in England under the Common Law Procedure Acts of the mid-nineteenth century.
The key research trap: do not conflate de intrusione with the broader concept of intrusion as a real property tort, which survived the writ system in modified form. The writ's specific trigger — entry by a stranger after a tenant's death, before the reversioner reclaimed — is narrower than the general law of entry and detainer. Historical sources that discuss "intrusion" as a property wrong may be describing the underlying tort, not the writ itself.
Researchers tracing the history of reversionary interests, landlord-tenant law, or the evolution of ejectment will find de intrusione useful as a marker for how the common law protected expectant estates before modern possessory actions consolidated these remedies. It sits within a cluster of writs — including novel disseisin and mort d'ancestor — that together formed the medieval real actions regime. Understanding which writ addressed which factual configuration is essential for reading primary sources accurately.
The Registrum Omnium Brevium (Register of Original Writs), cited by all three source dictionaries, is the authoritative primary source for the form and scope of this writ.
Historical Dictionary Support
Black's Law Dictionary (both editions) and Rapalje & Lawrence are in complete agreement on the substance: de intrusione was a writ of intrusion lying where a stranger entered after the death of the tenant, to the injury of the reversioner. All three sources cite the Registrum Originale at folio 233b as the primary authority, indicating they are drawing from the same root source rather than offering independent analysis.
None of the historical dictionaries elaborate on procedural mechanics — who brought the writ, against whom it ran, what the successful plaintiff recovered, or how it related to the contemporaneous writ of novel disseisin. This is a consistent gap across the shelf sources. Researchers needing that level of detail must go to Bracton, Littleton's Tenures, or Coke upon Littleton directly.
Rapalje & Lawrence's entry is notable for appearing mid-page alongside an unrelated entry (de homine capto in withernam), a typographical artifact of the original printing that occasionally causes confusion in digitized versions of that dictionary. The de intrusione entry is complete as quoted despite the apparent interruption.
Jurisdictional Note
De intrusione was an English common law writ and was never meaningfully transplanted into American practice. American courts inherited the underlying concept — that a reversioner has an actionable interest against wrongful intruders — but addressed it through ejectment and related modern forms rather than through the original writ. Research into American property disputes will not yield this writ; its relevance is confined to English legal history and comparative common law scholarship.