The thesis offers a social history of opium in colonial Assam by tracing the evolution of representations, perceptions and ideological positions on opium from local, national and transnational perspectives which enables a new mode of reading the province's specific encounter with colonialism and nationalism. It studies Assam's history through the prism of opium, particularly the interplay between state and society during the period 1828-1947, and focusses on three groups-addicts, peddlers and reformers-whose interaction defined the terrain of the opium question in order to challenge the economic and nationalist bias in the historiography. It interprets opium as a cultural commodity and social practice and reorients the framework of opium in India from export trade to domestic consumption, using opium addiction in Assam and the global prohibition campaign as the vantage point to explore the interplay between colonial policy, local dissent, nationalism and transnational factors in order to understand the role that opium played in shaping social, cultural and political discourses. The thesis highlights that the opium discourse epitomised the juncture where local phenomenon, national processes and transnational developments overlapped and produced a complex narrative of the intersection of notions of indolence, improvement and industry with modernities, resistance and localisms. As a social biography of opium in colonial Assam, the thesis addresses deficiencies in our understanding of opium in India as well as the wider historiography of opium and enables modes of interpreting Assam's unique encounter with colonialism and nationalism while also providing a framework to understand the influence of transnational factors in determining local facts. The thesis signals the centrality of transnational perspectives to drug history and is, therefore, both an attempt at recovery of local perspectives and regional specificities in the context of Assam as well as the insertion of locality into the global history of opium.