"The Rothschild conspiracy theory appears to have its origins in France in the mid-nineteenth century. In 1846 a left-wing polemicist and avowed anti-capitalist, Georges Dairnvaell, produced an antisemitic pamphlet in which he accused Nathan Rothschild, founder of the London branch of the family bank, of profiting from the Napoleonic Wars.
Writing under the pseudonym ‘Satan’, Dairnvaell claimed that Nathan Rothschild had been present at the Battle of Waterloo and on observing Napoleon would be defeated, had hot-footed it back across the English Channel to make a fortune on the London Stock Exchange ahead of other competitors. In fact, the account was by turns a total fabrication or relying on forged evidence, including a fake diary entry and fake newspaper quotes. Nathan Rothschild was not at the Battle of Waterloo but in London that day along with other traders. He bought stocks at the time but certainly made no great fortune.
Conspiracy theorists also claim that Rothschild spread false rumours that Napoleon had won the battle in order to make the price of stocks plummet so he could buy them cheaply and later sell them again at a vast profit. But this, too, is a lie, rather easily exposed: there is no record of a price slump that day.
Georges Dairnvaell had repeatedly libelled wealthy members of the Rothschild family in his writings before. He openly disliked both capitalists and Jews. This is undoubtedly the root cause of the first enduring myth about the Rothschild family, rather than anything Nathan Rothschild had said or done more than 30 years before"