Yoihi Isahaya

Yoichi Isahaya

Assistant Professor
History of Premodern Central Eurasia, Mongol Empire and Sciences

Contact: yoichi.isahaya@slav.hokudai.ac.jp

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Yoichi Isahaya


2015 Ph.D., Eurasian Studies, The University of Tokyo
2007 M.A., Asian History, Kobe University
2005 B.A., Asian History, Kobe University

Field of Study:

My research focuses on the exchange of knowledge in premodern Eurasia, especially in the two heydays of cross-cultural contact, that is, the periods of the Abbasid dynasty (750–1258) and the Mongol empire (1206–1368). My doctoral dissertation, Dialogue Concerning Two Astral Sciences: Naṣīr al-Dīn al-Ṭūsī, a Sage of Cathay, and Their Chinese Calendar in the Zīj-i Īlkhānī (c. 1272 CE), elucidated the Mongol “imperial ideology” in knowledge production through a cross-cultural dialogue between a Muslim polymath and a “sage of Cathay,” focusing on a Chinese calendar described in a Persian astronomical handbook compiled in 13th-century Iran. Through this “astronomical dialogue,” I shed light upon the Mongols’ attitude to the local forms of knowledge and sciences they encountered and mobilized across their empire. I have also actively presented and published my research. I produced a text, translation and study of the 9th-century revision by Thābit ibn Qurra (c. 836–901) of the Arabic Data by Euclid (fl. 300 BCE), which resulted in a book co-authored with Nathan Sidoli: Thābit ibn Qurra’s Restoration of Euclid’s Data: Text, Translation, Commentary (Cham: Springer, 2018). Our study contributed to shifting the understanding of the Islamicate scientific tradition from a significant conduit between ancient and modern “Europe” to a fertile field of scientific achievements in its own right.

Recent Publications (Selected):

(with Nathan Sidoli) Thābit ibn Qurra’s Restoration of Euclid’s Data: Text, Translation, Commentary. Cham:Springer, 2018.

Journal Articles and Book Chapters:

“Fu Mengzhi: “The Sage of Cathay” in Mongol Iran and Astral Sciences along the Silk Roads.” In Along the Silk Roads in Mongol Eurasia: Generals, Merchants, and Intellectuals, edited by M. Biran, J Brack & F. Fiaschetti, 238–254. Berkeley: University of California Press, 2020.
“The Mongol Impact on Astronomy: The Differentiation of Astronomy in the Eastern and Western Islamicate World.” In Voices of Three Generations: Essays in Honor of Seyyed Hossein Nasr, edited by M. Faghfoory & K. O'Brien, 333–349. Chicago: Kazi Publications, 2019.
“Sino-Iranica in Pax Mongolica: The Elusive Participation of Syriac-Rite Christians in the Ilkhanid Translation Project.” In Marco Polo and the Silk Road (10th–14th Centuries), edited by Rong X. & Dang B., 341–362. Beijing: Peking University Press, 2019.
"Mongol Eurasia from the View of Astral Sciences : Nasir al-Din al-Tusi (1201–1274) as a Cultural Pivot." Shien: The Journal of Historical Studies 79/2 (2019): 88–114. (in Japanese)
(with Nathan Sidoli) “Naṣīr al-Dīn al-Ṭūsī’s Comments on Euclid’s Data.” Historia Mathematica 47 (2019): 87–105.
(with Takashi Suga) “Reconstructing the Chinese-Hijri Calendar Conversion Table in the Ilkhanid Astronomical Handbook: Reconsidering the Inter-Dynastic Exchange of Astral Sciences in Mongol Eurasia.” In Proceedings of the Fifth Symposium on “Historical Astronomical Records and Modern Science,” edited by M. Sôma & K. Tanikawa., 252–277. Tokyo: National Astronomical Observatory of Japan, 2019. (in Japanese)
(with Jyuh Fuh Lin) “Entangled Representation of Heaven: A Chinese Divination Text from a Tenth-Century Dunhuang Fragment (P. 4071).” Historia Scientiarum 26/3 (2017): 153–171.
(with Mitsuaki Endo) “Persian Transcription of Yuan Chinese in the History of China of the Jāmiʿ al-Tawārīkh (Ms. Istanbul, Topkapı Sarayı, Hazine 1654).” The Economic Review 9 (2017): 123–161.
(with Mitsuaki Endo) “Yuan Phonology as Reflected in Persian Transcription in the Zīj-i Īlkhānī.” The Economic Review 8 (2016): 1–38.
“History of Science and Global History: Generating Puzzles to Reconsider Time, Space and a Science.” Journal of History of Science, Japan 53 (2014): 99–105. (in Japanese)
“The Tārīkh-i Qitā in the Zīj-i Īlkhānī: the Chinese Calendar in Persian.” SCIAMVS: Sources and Commentaries in Exact Sciences 14 (2013): 149–258.
“History and Provenance of the “Chinese” Calendar in the Zīj-i Īlkhānī.” Tarikh-e Elm: Iranian Journal for the History of Science 8 (2009): 19–44.
“The Modification of the Twelve-Animal Cycle in the Cultural Sphere of Literary Persian: A Consideration of the Twelve-Animal Cycle of the Timurid Period.” The Shirin: The Journal of History 91/3 (2008): 42–73. (in Japanese)



Invited Lectures (Selected):

“Maragha across the Euphrates: The Observatory in Mamluk Sources.” The Sixth Conference of the School of Mamluk Studies. “Mamluks and Asia: Views from the East.” Tokyo: Waseda University, 16th June 2019.
“From Alamūt to Marāgha: Religious Polarization and Scientific Commonalization.” Mongol Empire Spring Series M.E.S.S. 2019 Workshop “Religions in Mongol Eurasia.” Vienna: University of Vienna, 15th May 2019.
“Sciences in Zomia: Nizārī Ismāʿīlī Movements (1090–1256) in the Iranian Plateau.” International Conference “Medieval Zomias: Stateless Spaces in the Global Middle Ages.” Oxford: University of Oxford, 9th February 2019.
“Drawing Chinese Astronomy within Islamicate Astral Tradition: A Way of Representing Otherness in Case of 14th-Century Iran.” The Lecture Series of the Department of History at Fudan University. Shanghai: Fudan University, 18th December 2018.
“Cross-Cultural Highway in Mongol Eurasia: Chinese Calendar in the Zīj-i Īlkhānī.” International Workshop “Persian Historical Materials and the Research of Mongolian and Yuan History in the 13th–14th Centuries.” Hohhot: Inner Mongolia University, 26th August 2018.
“The “Second” Impact on Chinese Astral Tradition: Islamicate Astral Knowledge in the Yuan-Ming Period.” 2018 Annual Conference of the Center for Global Asia “Eurasian Connection.” Shanghai: NYU Shanghai, 20th August 2018.
“Mesoscopic Analysis for the Global Middle Ages: The Ilkhanid Translation Project as a Case.” Project Workshop “The Resonant Middle Ages: Transmission of Political and Scientific Thoughts between Medieval Europe, Persia, and China in Global History.” Tokyo: Waseda University, 7th July 2018.

Courses Taught:

- Global History
- Persianate World

Grants and Fellowships:

- Ilkhanid Translation Project: Toward a Mesoscopic History of Mongol Eurasia (JSPS: Grant-in-Aid for JSPS Fellows, 2018–2019)
- Sophistication of Timekeeping in the 13th and 14th Centuries Persianate Societies (JSPS: Grant-in-Aid for JSPS Fellows, 2011–2014)
- Chinese Calendar in the Islamicate Astronomical Handbooks (Zījes) (JSPS: The Institutional Program for Young Researcher Overseas Visits at The University of Tokyo, 2012)
- Transmission of the Chinese Calendar into the Persianate World (JSPS: Excellent Young Researcher Overseas Visit Program, 2010–2011)
- Transmission of the Chinese Calendar into the Persianate World (JSPS: Grant-in-Aid for JSPS Fellows, 2009–2011)

Professional Service: