seisin

Seisin is a historic term in English property law referring to the possession of a feudal estate in land. It signified the right to possess and the actual possession of the land, and it was central to the way land was granted and held in the medieval period.

Under the feudal system, a landholding passed not only by grant but by a ceremony called livery of seisin, in which the transfer of possession was made tangible—often a symbolic delivery of soil or a similar token to the feoffee. Seisin thus marked the moment at which a person acquired the right to use and enjoy the land. The concept distinguished possession of a freehold or other inheritable estate from mere occupancy, and it enabled the grantee to sue and be sued over the land.

There were distinctions within seisin: seisin in fact (the corporeal possession of the land) and seisin in law (the legal right to hold the land by virtue of the estate, even if actual possession was delayed). Over time, ceremonial transfers and the strict medieval structure of tenure faded, and the formal notion of seisin diminished in importance.

In modern usage, seisin survives mainly as a historical term and in fixed phrases such as “seised of” or “seised of an estate,” meaning legally in possession of land. The concept remains relevant for understanding the development of real property law, illustrating how possession, title, and transfer historically intertwined in feudal tenure.