In the year 1677 he settled down in Hanover, where he became busily engaged in affairs of state, and was specially occupied with historical matters. In the Harz Mountains he had works constructed for carrying off the floods which did damage to the mines there. Notwithstanding these manifold occupations he invented the differential calculus in 1677, on occasion of which there arose a dispute between him and Newton, which was carried on by the latter and the Royal Society of London in a most ungenerous manner. For it was asserted by the English, who gave themselves the credit of everything, and were very unfair to others, that the discovery was really made by Newton. But Newton’s _Principia_ only appeared later, and in the first edition indeed Leibnitz was mentioned with commendation in a note which was afterwards omitted. From his headquarters in Hanover, Leibnitz, commissioned by his prince, made several journeys through Germany, and also went to Italy in order to collect historical evidence relative to the House of Este, and for the purpose of proving more clearly the relationship between this princely family and that of Brunswick-Lüneburg. At other times he was likewise much occupied with historical questions. Owing to his acquaintance with the consort of Frederick I. of Prussia, Sophia Charlotte, a Hanoverian princess, he was enabled to bring about the foundation of an Academy of Science in Berlin, in which city he lived for a considerable time. In Vienna he also became acquainted with Prince Eugène, which occasioned his being appointed finally an Imperial Councillor. He published several very important historical works as the result of this journey. His death took place at Hanover in 1716, when he was seventy years of age.[242]