Definition
A Latin term from the old common law meaning a demise, lease, or letting — that is, a transfer of possession of land by way of lease or grant. The term appears most prominently in the phrase *ex demissione* (on the demise of), which was a formal element of the old action of ejectment. In that procedural context, demissio described the fictional leasehold relationship by which the nominal plaintiff was said to hold the land at issue, on the demise of — that is, by lease from — the actual claimant whose title was being tested.
The term also appears in the phrase *demissio coronae* (demise of the crown), referring to a transfer or descent of the Crown itself, as by the death or abdication of the sovereign.
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Common Confusion
DEMISSIO should not be confused with DEMISE in its modern sense of death or end. In legal Latin, demissio means a lease or grant of possession — an act of transferring an estate — not a death. The confusion arises because DEMISE evolved in English legal usage to mean both a lease of land and the death of a sovereign (or any person), the latter sense arising from the same idea that the Crown "descends" or is "transferred" at a monarch's death. In historical sources, demissio is consistently the lease or transfer sense. See also: DEMISE OF THE KING.
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Why It Matters in Research
Demissio is almost exclusively a term of art in historical English common law pleading and will appear in pre-19th-century English reports, writs, and treatises rather than in modern legal materials. Researchers encountering it in primary sources need to understand its procedural home: the action of ejectment.
The old action of ejectment was built on a framework of legal fictions. Rather than allowing the actual claimant to sue directly for title, the courts required the real plaintiff to be cast as a lessor who had supposedly leased the land to a fictitious lessee (the nominal plaintiff, classically "John Doe"). The declaration in such an action would recite that the fictitious plaintiff held the land *ex demissione* — on the demise of, i.e., by lease from — the true claimant. The phrase therefore appears in case titles and pleadings as a structural marker, not as a description of any real transaction.
This means that when demissio or ex demissione appears in an old case title, it signals:
(1) The proceeding is an ejectment action testing title to real property.
(2) The named lessor after the phrase is the real party in interest, not the nominal plaintiff.
(3) The lease itself is a legal fiction; no actual demise took place.
Reform of the action of ejectment in England (the Common Law Procedure Act 1852) and analogous reforms in American states eliminated the fictitious-plaintiff device, so demissio effectively disappeared from live pleading after the mid-19th century. Researchers working in post-reform materials will not encounter it except in historical discussion.
The demissio coronae usage appears in constitutional and public law commentary — particularly Blackstone — and refers to the legal principle that the Crown never "dies": it transfers or demises upon the sovereign's death, ensuring continuity of the royal office.
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Historical Dictionary Support
Both Burrill and Black agree on the core meaning: demissio is a demise or lease, and its operative significance is procedural, tied to the ejectment action's ex demissione formula.
Burrill adds the broader sense of "transfer" generally and specifically flags demissio coronae with a cite to Blackstone's Commentaries — a usage Black's omits. Neither source addresses the substantive law of ejectment in depth under this entry; both treat demissio as a cross-reference term pointing researchers toward DEMISE and EX DEMISSIONE.
Neither historical dictionary addresses the procedural reform context — namely, that the fictitious ejectment apparatus that gave ex demissione its practical meaning was already being abolished around the time these dictionaries were compiled. This is the most significant gap: a researcher consulting Burrill or Black's alone would not be warned that demissio was already an archaism by the 1890s.
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Jurisdictional Note
Demissio is a term of English common law origin. American courts adopted the same ejectment fiction and used ex demissione in case titles through the early-to-mid 19th century before state procedural reforms displaced it. The term has no meaningful life in civil law jurisdictions.
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