Isaac Newton’s Philosophiae naturalis principia mathematica is widely regarded as one of the most important publications in the history of science. His universal laws of motion and of gravity and his mathematical and empirical approach to physics would dominate scientific thinking for about two centuries. The reception of the first edition of the Principia (1687), especially on the Continent, was of crucial importance for the spread of Newtonianism beyond the British Isles. A new witness to this process is now being brought to light: a copy of the first edition of the Principia, annotated by the Amsterdam merchant, writer and amateur mathematician Adriaen Verwer. A man who deserves to be called the first continental Newtonian – although he did not always agree with the British scientist, and 'misused' him for his own purposes.