Taqi al-Din Muhammad ibn Ma'ruf ash-Shami al-Asadi (Arabic: تقي الدين محمد بن معروف الشامي, Turkish: Takiyüddin or Taki) (1526–1585) was an Ottoman polymath active in Istanbul. He was the author of more than ninety books on a wide variety of subjects, including astronomy, clocks, engineering, mathematics, mechanics, optics and natural philosophy.[1] In 1574 the Ottoman Sultan Murad III invited Taqī ad-Dīn to build the Constantinople observatory. Using his exceptional knowledge in the mechanical arts, Taqī ad-Dīn constructed instruments like huge armillary and mechanical clocks that he used in his observations of the Great Comet of 1577.