This course introduces students to key issues around which environmental history as a field evolved. Additionally, it also introduces the methods through which the quotient of human environment equation as an analytical lens emerged for historical studies. The course follows a non-linear pattern in its organisation. It introduces the historical and historiographical context within which environmental history emerged as a technique of historical enquiry and subsequent conceptual developments in this field. This is a 20^th century phenomenon. It then reverts back in time to undertake a broad survey of the key concerns and questions of the human environment equation that emerge in the historical enquiries through prehistoric, early history era, middle ages and all the way to the emergence of modern and contemporary historical developments.