The Drain of Wealth theory was first systematically articulated by Indian nationalists like Dadabhai Naoroji, R.C. Dutt, and M.G. Ranade during the British colonial period. They argued that Britain was continuously extracting wealth and resources from India through various means like salaries, pensions, trade surpluses, and interest payments on loans, for which India received no commensurate economic return. This drained India's capital and hindered its economic development, while supposedly contributing to Britain's industrialization and prosperity.