In the last quarter of the 19th century, Assam’s oilfields became part of the larger global petroleum economy and thus played a key role in the British imperial economy. After decolonisation, the oilfields not only turned out to be the subject of intense competition in a regional economy, they also came to be identified with the rights of the community, threatening the federal structure and India’s development paradigm. This paper is an attempt to locate the history of Assam’s oil in the large imperial, global and national political economy. It re-examines the science and polity of petroleum exploration in colonial Assam.