mid-14c., possessioun, "act or fact of holding, occupying, or owning; a taking possession, occupation," also "thing possessed, that which is possessed, material or landed property" (in plural, goods, lands, or rights owned), from Old French possession "fact of having and holding; what is possessed;" also "demonic possession," and directly from Latin possessionem (nominative possessio) "a seizing, possession," noun of action from past-participle stem of possidere "to possess" (see possess).

The legal property sense is earliest; the demonic sense in English, "state of being under the control of evil spirits or of madness," first is recorded 1580s. Phrase possession is nine (or eleven) points of the law is out of a supposed 10 (or 12). With eleven from 1640s; with nine from 1690s.

St. Jerome in his 'Life of St. Hilarion' has given us a graphic account of the courage with which that saint confronted, and the success with which he relieved, a possessed camel. [Lecky, "History of European Morals"]