Mortmain is the perpetual, inalienable ownership of real estate by a corporation or legal institution; the term is usually used in the context of its prohibition. Historically, the land owner usually would be the religious office of a church; today, insofar as mortmain prohibitions against perpetual ownership still exist, it refers most often to modern companies and charitable trusts. The term "mortmain" is derived from  Mediaeval Latin mortua manus, literally "dead hand", through Old French morte main.