The purpose of this dissertation is to describe in detail the efforts made to protect natural indigo the blue dyestuff extracted from the leaves of the indigo plant (Indigofera tinctoria) - against the market competition of cheaper and purer synthetic indigo - which was derived from coal-tar hydrocarbons. Throughout the nineteenth century British India was the pre-eminent producer and supplier to the West of indigo for its thriving textile industry. The introduction of synthetic indigo on the market in 1897 by two German companies threatened to end Indias dominant role in the indigo trade. To counteract competition from the synthetic substitute the European planters living in India, supported by the colonial and the national governments, conducted scientific research in the laboratories and farm stations. This dissertation fundamentally focuses on these scientific efforts made in India and England, and contributes to the scientific and technological history of Modern South Asia.