From the mid-eighteenth century, there was a new phase of change. Commercial centres such as Surat, Masulipattanam and Dhaka, which had grown in the seventeenth century, declined when trade shifted to other places. As the British gradually acquired political control after the Battle of Plassey in 1757, and the trade of the English East India Company expanded, colonial port cities such as Madras, Calcutta and Bombay rapidly emerged as the new economic capitals.