Cohn's seminal contributions included work on India's caste system, by which he established that caste was solidified as a concept by the British codification of it, as well as the establishment of historical anthropology as a means to link the disciplines of anthropology and history. This work intersected with earlier work about syncretism between these two disciplines by Alfred L. Kroeber, as well as essays by Clifford Geertz. Cohn's works include Colonialism and its Forms of Knowledge (1996), An Anthropologist Among the Historians (1987) and India: The Social Anthropology of a Civilization (1971). His students, including Dipesh Chakrabarty, Nicholas Dirks, Ronald Inden, and Ritty Lukose have continued in the vein of his work. His work has been closely studied by members of Subaltern Studies, especially Ranajit Guha.