A legal concept from early English property law that continues to influence certain concepts in the modern law of real property and is thus helpful and, at times, essential to understanding this area of the law. In brief, the term refers to the possession of land. However, the nature of this possession is a complex matter deserving a full academic explanation. In early English property law, a landholder was considered "seised of" his estate- an idea which somewhat overlaps with the modern meaning of ownership- but differs in a number of respects. Seisin was passed through a ceremony known as "livery of seisin".