- Dadabhai Naoroji is known as the 'Grand Old Man of India' and was a prominent nationalist leader, economist, and politician. - The "Drain of Wealth" theory was one of the earliest and most influential critiques of the economic impact of British colonialism in India. - The book provided statistical data and analysis to support his arguments, documenting the transfer of wealth through various means like salaries of British officials, military expenditure, profits of British companies, etc.