seizin

Seizin, also spelled seisin, is a historical legal concept in common law referring to the possession of a freehold estate in land or the right to enjoy it. The term derives from Old French saisine and medieval Latin sources meaning possession or seizure. In feudal England, the transfer of land by feoffment required a transfer of seisin: the actual moment when the grantee received physical possession of the land and thus the legal right to hold it.

There are two related ideas: seisin in fact (actual possession) and seisin in law (recognition by the law of the possessor’s rights, sometimes even without actual possession). In ejectment actions, the plaintiff's case historically depended on proving seisin appropriate for the freehold; later, the modern law replaced the requirement with title and possession standards.

Modern relevance: Seizin is largely historical and rarely used in contemporary property transactions, which speak in terms of title, ownership, and possession rather than feudal seisin. The concept, however, remains important for understanding old deeds, feudal tenure, and the evolution of property law.