Dadabhai Naoroji propounded the theory of 'Drain of Wealth' in the 19th century. The colonial period was characterized by the exploitation of Indian resources. The primary motive of Britain to conquer India was to own a perennial source of cheap raw materials to feed its own industrial base in Britain. On the other hand, income of Indians was spent on expensive imports of finished goods from Britain which made Britain richer on the expense of India. Further, British Government used India's manpower to spread its colonial base outside India. Indians served in the British army at lower salaries than their British counterparts. Also, the expanses of war and administrative expenses that were incurred by the British Government to manage the colonial rule in India were drawn from the revenue collected from Indiana and the export surplus generated through foreign trade of India. Thus, the British rule drained out Indian wealth for the fulfillment of its own interests.