Albert Einstein famously quipped, ‘Do not worry about your difficulties in Mathematics. I can assure you mine are still greater.’ In 1940 he had major difficulties, but they had nothing to do with mathematics. An acquaintance of his, the polymath and collector Abraham Yahuda, had four years earlier acquired a huge swathe of Isaac Newton’s manuscripts after their sale at Sotheby’s, and Einstein was now seeking a home for them. Alas, even the discoverer of the theory of relativity found there were limits to his powers of persuasion. Yale claimed that they lacked the space to house the papers, while Harvard reminded him that there was a war going on. Princeton, meanwhile, politely refused the material on the grounds that its content was not scientific.

The Princeton librarians’ assessment was correct. For the papers revealed that perhaps the greatest Western scientist before the 20th century – whose exposition of the theory of universal gravitation in his Principia (1687) had provided