There is a story that is commonly told in Britain that the colonisation of India – as horrible as it may have been – was not of any major economic benefit to Britain itself. If anything, the administration of India was a cost to Britain. So the fact that the empire was sustained for so long – the story goes – was a gesture of Britain’s benevolence.

New research by the renowned economist Utsa Patnaik – just published by Columbia University Press – deals a crushing blow to this narrative. Drawing on nearly two centuries of detailed data on tax and trade, Patnaik calculated that Britain drained a total of nearly $45 trillion from India during the period 1765 to 1938.