This doctrinal thesis critically examines the traditional understanding of the definition of occupation under international humanitarian law, which requires the physical presence of an occupying power’s troops for a territory to be considered under its effective control and thus occupied. By analysing the preparatory work behind Article 42 Hague Regulations 1907, case law and contemporary state practices, this thesis demonstrates that the criteria for the establishment of occupation do not necessarily mirror those required for the maintenance of an occupation that has already been established. This study posits that the correct test for determining the maintenance of an already established occupation is the occupying power’s continued possession of effective control and its retained ability to exercise authority over the occupied territory, to the exclusion of any rival power. Notably, this thesis demonstrates how these criteria can be met even without the occupying power having its ‘boots on the ground’ in the occupied territory. This interpretation allows the law of occupation to better address the legal challenges posed by modern occupations and account for more advanced methods of exerting control over foreign territory.