Military occupation, also called belligerent occupation or simply occupation, is temporary hostile control exerted by a ruling power's military apparatus over a sovereign territory that is outside of the legal boundaries of that ruling power's own sovereign territory. The controlled territory is called occupied territory, and the ruling power is called the occupant. Occupation's intended temporary nature distinguishes it from annexation and colonialism. The occupant often establishes military rule to facilitate administration of the occupied territory, though this is not a necessary characteristic of occupation.
The rules of occupation are delineated in various international agreements—primarily the Hague Convention of 1907, the Geneva Conventions, and also by long-established state practice. The relevant international conventions, the International Committee of the Red Cross, and various treaties by military scholars provide guidelines on topics concerning the rights and duties of the occupying power, the protection of civilians, the treatment of prisoners of war, the coordination of relief efforts, the issuance of travel documents, the property rights of the populace, the handling of cultural and art objects, the management of refugees, and other concerns that are highest in importance both before and after the cessation of hostilities during an armed conflict. A country that engages in a military occupation and violates internationally agreed-upon norms runs the risk of censure, criticism, or condemnation. In the contemporary era, the laws of occupation have largely become a part of customary international law, and form a part of the law of war.