administration of occupied territory by an occupying power, including the exercise of executive, legislative, and judicial authority. In international law, territory is considered occupied when it is actually under the authority of hostile armed forces. The necessity for military government arises from the failure or inability of the legitimate government to exercise its functions. It is immaterial whether or not the government over an enemy's territory consists of a military or civil or mixed administration.

Because it is in connection with belligerent occupation that the general concept of military government evolved, the definition does not cover cases in which military forces have been stationed in neutral or friendly territory and share with local civil authorities the responsibilities of administration. Also, military government must be distinguished from military law and martial law. Military law is the code that regulates the conduct of members of the armed forces but does not apply to civilians. Martial law is the temporary government of the civil population through the military forces without the authority of written law, as necessity may require; it is invoked only in domestic territory.