The Diwani- the document that handed over the three richest provinces in India to the East India Company, 1765. Later, the British dignified the document by calling it the Treaty of Allahabad, though Clive had dictated the terms & a terrified Shah Alam simply waved them through.

As Ghulam Hussain Khan put it ‘A business of such magnitude & which at any other time would have required the sending of wise ambassadors & able negotiators, was done and finished in less time than would usually have been taken up for the sale of a jack-ass, or a beast of burden’

Before long the EIC was straddling the globe. Almost single-handedly it reversed the balance of trade, which from Roman times on had led to a continual drain of Western bullion eastwards.

The document not only gave a veneer of Mughal legitimacy for the Company’s conquests, it also potentially gave the EIC the right to tax 20 million people, and generate an estimated revenue of between £2 million and £3 million a year– a massive windfall by 18thC standards.

It was a hugely significant moment: with one stroke of the pen, in return for a relatively modest payment of Rs2.6 million, the Emperor agreed to recognise all the Company’s conquests and hand over to it financial control of all north-eastern India.

Seizing the many riches of Bengal with its fertile paddy fields and rice surpluses, its industrious weavers and rich mineral resources, opened up huge opportunities for the Company and would generate the finance to continue building up the most powerful army in Asia.

The vast revenues of Bengal, which had for so long powered the Mughal exchequer, could, Clive knew, make the Company as unassailable as the Mughals had once been – and provide the finance for perhaps, one day, conquering the rest of the country.

250 EIC clerks backed by the military force of 20,000 sepoys would now run the finances of India’s three richest provinces, effectively ending independent government in Bengal for 200 years. For a company with profit as its main raison d’être, this was a transformative moment

Another view of the signatures on the Diwani. The English text can be read here:
https://en.m.wikisource.org/wiki/Treaty_of_Allahabad