From Samarkand to Istanbul: Ali Qushji's Astronomical Legacy

Ali Kuşçu was a distinguished scholar, mathematician, and observer who lived in the 15th century and is regarded as one of the founders of astronomical education in Osmanlı. He is believed to have been born in Samarkand and to have acquired the epithet “Kuşçu” because his father served as the falconer-in-chief (doğancıbaşı) to Ulugh Bey. As a youth, he received his education at the Ulugh Bey Observatory, one of the most advanced scientific centers of his time. There he studied mathematics astronomy and geometry under scholars such as Kadızâde-i Rûmî and Jamshid al-Kashi. This environment fostered a research culture grounded in observational methods and precise calculations. Ali Kuşçu developed deep expertise through his work on trigonometric measurements astronomical tables and observational instruments.

^{Representation of Ali Kuşçu (Generated by Artificial Intelligence)}

After the death of Ulugh Bey the scientific community in Samarkand weakened and Ali Kuşçu first moved to Tabriz then to the court of Akkoyunlu ruler Uzun Hasan. However what distinguished him in the history of science was his arrival in Ottoman lands at the invitation of Fatih Sultan Mehmed. Fatih’s personal reception of Ali Kuşçu demonstrated the high value placed on knowledge in the scientific culture of the era. The Sultan provided him with both material and spiritual support and established a specialized faculty for astronomical instruction at the Ayasofya Medresesi. Thus astronomy in the Ottoman Empire became an independent field of study for the first time. Ali Kuşçu’s arrival in Istanbul was not merely the migration of a scholar but a turning point that redirected the course of Ottoman scientific tradition.

Ali Kuşçu’s most important astronomical work is el-Fethiyye fi’l-Hey’e. Expanding upon his earlier Persian treatise Risâle der Heyʾe he composed this work in Arabic and provided comprehensive information on the motions of celestial bodies the positions of stars planetary orbits and spherical trigonometric calculations. While adhering to the geometric model of the classical Ptolemaic system he reinterpreted it using observational data. In his treatise Fâide fî Eşkâli Utarid he also made a significant contribution by critiquing specific errors in Ptolemy’s model of Mercury. In this regard Kuşçu was a pioneer in introducing the tradition of critical observation to the Ottoman Empire.

During his time in Istanbul Ali Kuşçu was not only a teacher but also an effective transmitter and institutionalizer of science. In addition to his duties at the Ayasofya Medresesi he collaborated with Molla Hüsrev to design the curriculum (nizamname) of the Sahn-ı Seman Medreseleri. His most well-known mathematical work is the er-Risâletü’l-Muhammediyye fi’l-Hisâb written in honor of Fatih and taught for many years. In the fields of theology and logic he also exerted influence through his commentary Şerhu’t-Tecrîd on the work of Nasîrüddin-i Tûsî.

The Samarkand legacy that he brought to the Ottoman Empire was not limited to theoretical knowledge; it also introduced the tradition of observatories instrument-making and observational techniques to Istanbul. In this way Ali Kuşçu served as a bridge in the transition of Islamic astronomy from East to West.

Today in the literature of the history of science this transfer of knowledge he initiated is referred to as the “second Samarkand influence.”

Ali Kuşçu died in Istanbul on 16 December 1474. The students and works he left behind laid the foundation for the institutionalization of scientific astronomy in the Ottoman Empire and shaped the content of courses taught in observatories and medreses. Ali Kuşçu’s legacy continues to remind us of the boundless nature of knowledge and the role of scientists as cultural bridges.