In 1760, the Persian Gulf port of Basra became a trading center for the British East India Company, and many Jews who had played a significant part in English trade in the region progressively migrated on to India from Basra–and Baghdad. They originally arrived in Surat, a port on India’s west coast. Nearly 100 Jews from Aleppo, Baghdad, and Basra made up the Arabic-speaking Jewish commercial colony of Surat at the end of the 18th century.
In India, the terms “Baghdadi” and “Iraqi” originally referred to Jews from the region between the Tigris and Euphrates rivers, which had been a center of Jewish scholarship and culture for generations. However, the word evolved to cover both Arabic-speaking Jews from Syria and other parts of the Ottoman Empire, as well as non-Arabic-speaking Jews from Persia and Afghanistan. Sephardim was a term used by Baghdadi Jews to refer to themselves, referring to their liturgical heritage rather than their geographical origins.
Surat’s role as a port waned as the British presidencies of Calcutta and Bombay grew, and the Jewish businessmen who lived there relocated to these fast-growing economic cities. Famous Iraqi families profited as merchants or intermediaries for the huge cotton, jute, and tobacco processing companies, thanks to British encouragement. The opium trade was also lucrative for certain Baghdadi Jews.
Source: https://www.myjewishlearning.com/article/the-jews-of-india/