For more than a hundred years, from the end of the 18th century to the eve of the First World War, opium was the main commodity exported from India to China. During most of this period, it was the second largest source of revenue, after land revenue, for the British Indian Empire. The article was sold for narcotic use in the Chinese market. Opium was produced in Gangetic eastern and northern India, and the central Indian plateau region of Malwa. The produce of the former zone was a monopoly of the colonial state. The production, processing, and sale of the drug was directly controlled by the government. Malwa was entirely under princely rule. Princely states were administered indirectly, had a measure of autonomy, and were subject to the overall authority of the British. Indirect rule made it difficult for the colonial government to regulate the opium trade of central and western India effectively. It pursued a different policy with regard to the opium produce of Malwa, permitting transit of the commodity for export from Bombay on the payment of a duty.
The worldwide campaign against the opium trade that gathered momentum in the late 19th century contributed to the decline of the trade. Between the first decade of the 20th century and the end of the First World War, the British withdrew from the trade. International agreements for drug control led to rigorous imposition of restrictions on production and sale, terminating official involvement in the export of opium other than that for medical use. This brought to an end the career of Indian opium as a major colonial commodity.