from his friends even after all his efforts. He must have succeeded in acquiring it later since Taqī al-Dīn's work on optics would eventually make it to the Bodleian Library as Marsh 119. It was originally in the Golius collection so it is clear that Golius eventually succeeded at acquiring it. According to Salomon Schweigger, the chaplain of Habsburg ambassador Johann Joachim von Sinzendorf, Taqi al-Din was a charlatan who deceived Sultan Murad III and had him spent enormous resources. At the age of 59, after authoring more than ninety books, Taqī al-Dīn passed away in 1585. The Constantinople Observatory Taqī al-Dīn was both the founder and director of the Constantinople Observatory, which is also known as the Istanbul Observatory. This observatory is frequently said to be one of Taqī al-Dīn's most important contributions to sixteenth-century Islamic and Ottoman astronomy. In fact, it is known as one of the largest observatories in Islamic history. It is often compared to Tycho Brahe's Uraniborg Observatory, which was said to have been the home to the best instruments of its time in Europe. As a matter of fact, Brahe and Taqī al-Dīn have frequently been compared for their work in sixteenth-century astronomy. The founding of the Constantinople Observatory began when Taqī al-Dīn returned to Istanbul in 1570, after spending 20 years in Egypt developing his astronomy and mathematical knowledge. Shortly after his return, Sultan Selīm II appointed Taqī al-Dīn as the head astronomer (Müneccimbast), following the death of the previous head astronomer Muṣṭafā ibn ҁAlī al-Muwaqqit in 1571. During the early years of his position as head astronomer, Taqī al-Dīn worked in both the Galata Tower and a building overlooking Tophane. While working in these buildings, he began to gain the support and trust of many important Turkish officials. These newfound relationships lead to an imperial edict in 1569 from Sultan Murad III, which called for the construction of the Constantinople Observatory. This observatory became home to many important books and instruments, it had sixteen assistants who helped with the making of scientific instruments, as well as many renowned scholars of the time. While there is not much known of the architectural characteristics of the building, there are many depictions of the scholars and astronomical instruments present in the observatory. It was from this observatory that Taqī al-Dīn discovered the Great Comet of 1577, Murad III taught of the comet as a bad