Sevim Tekeli was a pioneering Turkish historian of science whose scholarly work transformed understanding of Ottoman astronomy and technology. Born on 22 December 1924 in İzmir, she grew up in a family shaped by public service. Her father, Osman Nuri Tekeli, served as a provincial governor in various regions of Turkey, which meant that her early education took place across different cities. Her mother was Hamide Tekeli. After completing primary schooling in several locations, she attended the İzmir Girls’ High School and graduated from the American Girls’ High School of Üsküdar. This mixed educational background exposed her to both Turkish and Western influences at a formative age.
In 1948 she entered the Department of Philosophy at Ankara University’s Faculty of Language, History and Geography. She graduated in 1951. During her undergraduate years she came under the strong influence of Professor Aydın Sayılı, the founder of the academic study of the history of science in Turkey. Sayılı had studied under George Sarton at Harvard and established Turkey’s first chair of the history of science. Inspired by his lectures, Tekeli decided to devote her career to this emerging field. In 1951 she began doctoral work under his supervision, and in 1952 she was appointed research assistant in the newly formed History of Science Chair at the same faculty.
At the time, research materials on Ottoman science were scarce in Turkey. Manuscripts were scattered, catalogues were incomplete, and few scholars had examined the technical content of Ottoman astronomical texts. Tekeli set out to change this situation. Her doctoral thesis, completed in 1956 (sometimes dated 1959 in secondary sources), compared the observational instruments of three major astronomers: Nasir al-Din al-Tusi of the thirteenth-century Maragha Observatory, Taqi al-Din of the sixteenth-century Istanbul Observatory, and Tycho Brahe of late-sixteenth-century Denmark. The study demonstrated striking parallels between the instruments used at these observatories and challenged prevailing assumptions that Ottoman science had lagged far behind European developments. An English summary of the thesis, prepared with Sayılı’s help, attracted international attention and helped introduce Taqi al-Din to a wider scholarly audience.
Tekeli continued to focus on Taqi al-Din (also known as Takiyüddin Raşid or Taqi al-Din Muhammad ibn Ma’ruf). For her associate professorship she examined his astronomical work Sidretü’l-Müntehâ and the state of sixteenth-century Ottoman astronomy. In 1966 (or 1967 according to some accounts) she submitted a major study of Taqi al-Din’s treatise on mechanical clocks, entitled The Brightest Stars concerning the Construction of Mechanical Clocks. This work, published in Ankara in 1966, established that Taqi al-Din was one of the most important astronomers and technologists of the sixteenth century. He had constructed sophisticated observational instruments and mechanical clocks that ranked among the most advanced of their time. Through careful textual analysis and comparison with contemporary European sources, Tekeli showed that the Istanbul Observatory, founded in 1575 under the patronage of Sultan Murad III, represented a high point of Ottoman scientific achievement before its destruction in 1580.
Beyond Taqi al-Din, Tekeli investigated other aspects of Islamic and Ottoman science. She studied the maps of Piri Reis and the work of Muhyi al-Din al-Maghribi. She explored the transmission of Greek scientific knowledge through the Islamic world to Renaissance Europe, the comparative development of scientific institutions in the Ottoman Empire, Western Europe and Russia in the seventeenth century, and the role of Byzantium in the birth of modern science. In 1975 she published Modern Bilimin Doğuşunda Bizans’ın Etkisi (The Influence of Byzantium on the Birth of Modern Science). She also contributed to studies of the thirteenth-century engineer al-Jazari; in 2002 she collaborated with two former students, Melek Dosay Gökdoğan and Yavuz Unat, on a Turkish translation of one of al-Jazari’s major engineering treatises.
Tekeli’s academic career advanced steadily. After completing her doctorate she spent time in England in 1959, attending courses at the Department of the History of Science at University College London. In 1964 she conducted research in Paris. She became associate professor in 1960 and full professor in the mid-1960s, making her one of the first, if not the first, women professors of the history of science in Turkey and possibly the world. From 1982 until her retirement in 1993 she served as head of the Philosophy Department at Ankara University’s Faculty of Language, History and Geography. Throughout her career she trained a generation of Turkish historians of science and helped institutionalise the discipline.
She participated in international scholarly life. In 1971 she travelled to Iran as a guest of the Regional Cooperation for Development organisation linking Turkey, Pakistan and Iran. In 1973 she contributed to UNESCO’s celebrations of the 500th anniversary of Copernicus’s birth and received a certificate of appreciation from the Polish government. She was a founding member of the Turkish-Arab Relations Foundation, the Turkish Philosophical Society and the Turkish Society for the History of Science. For seven years she served as a full member and executive board member of the Atatürk Cultural Centre, where she also chaired the Science and Philosophy section.
Tekeli played a central role in introducing the history of science into Turkish secondary education. Under her leadership, members of the History of Science Department prepared the first high-school textbook on the subject, Bilim Tarihi, published in 1993. Expanded editions followed in 1997 and 1999 under the title Bilim Tarihine Giriş (Introduction to the History of Science). These books became standard university and school texts and helped create a broader public awareness of the scientific heritage of Islamic and Ottoman civilisations.
Her work was characterised by rigorous textual scholarship, comparative method and a determination to let the primary sources speak for themselves. She repeatedly emphasised that the historian’s duty is to record facts accurately rather than to serve national myths. In her own words, when she discovered unexpected parallels between Ottoman and European instruments she felt confusion about the conventional narratives of science history, yet she remained committed to presenting the evidence as she found it.
Sevim Tekeli died in Ankara on 16 December 2019 at the age of ninety-four, six days before her ninety-fifth birthday. She left behind a substantial body of books, articles and trained students that continue to shape the study of Ottoman science. She is remembered as Turkey’s first woman historian of science, a leading authority on Taqi al-Din and Ottoman astronomy, and a key figure in the institutionalisation of the history of science as an academic discipline in her country. Through patient archival work and clear comparative analysis she demonstrated that the Ottoman scientific tradition was more sophisticated and more closely connected to broader Eurasian developments than earlier generations of historians had recognised.