The Mongols, who had consolidated the powers of the steppe zone by the beginning of the thirteenth century, evolved their tribal confederation into the Eurasian empire through expansion to the adjacent sedentary world. In consequence, Persianate and Chinese societies both formed parts of the largest landmass empire in history. After the dissolution of the empire, the Ilkhanids (c. 1260–c. 1335) in Iran and Iraq continued to be a major ally of the Yuan dynasty (1271–1368). This close political relationship with China facilitated the influx of Chinese commodities, ideologies and technologies into the Ilkhanid realm. My principal aim is to find, calibrate and assess a wide range of “Chinese knowledge” and its donors in the Ilkhanids by means of Persian sources. In my dissertation, I have elucidated an actual phase of cross-cultural dialogue between Naṣīr al-Dīn al-Ṭūsī (1201–1274) and a “sage of Cathay” through a comprehensive investigation into the Chinese calendar in Ṭūsī’s Zīj-i Īlkhānī (c. 1272). Next, I will deal with a fourteenth-century commentary upon the Zīj-i Īlkhānī which interpreted a part of the Chinese calendar with the Ptolemaic geometrical model, of which Islamicate astronomers had mastery. Therefore, this material will give us insight into the way that an Islamicate intellectual appropriated Chinese astronomy into his own astral tradition. I will also work on the Tangsūq-nāma (early 14c.), the Persian translation of a Chinese medical compilation—astral and medical sciences both served as core learning at the Mongol courts. The work includes a long introduction by Rashīd al-Dīn (1247–1318), which provides us with full of fresh observation of the Chinese people, knowledge and society.
- Ph.D (2015). Institution: Graduate School of Arts and Sciences, the University of Tokyo. Supervisor: HANEDA Masashi. 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 AD) (in Japanese).
- M.A. (2007). Institution: Graduate School of Humanities, the Kobe University. Supervisor: MASHITA Hiroyuki. Master’s Thesis: Twelve-Year Animal Cycle in the Timurid Period (in Japanese).
- B.A. (2005). Institution: Faculty of Letters, the Kobe University. Major: History of Asia.
Positions & Fellowships
- 2015–Present. Position: Post-Doctoral Fellow Program: The ERC Project: “Mobility, Empire and Cross Cultural Contacts in Mongol Eurasia”. Institution: the Hebrew University of Jerusalem. Project Title: Ilkhanid China: Chinese Knowledge in Persian. Supervisor: Michal BIRAN (the Hebrew University of Jerusalem)
- 2011–2014. Position: Research Fellow. Program: Research Fellowship for Young Scientists at the Japan Society for the Promotion of Science (JSPS) Institution: Institute for Advanced Studies on Asia, the University of Tokyo. Project Title: Sophistication of Timekeeping in the 13th and 14th Centuries Persianate Societies. Supervisor: MORIMOTO Kazuo (the University of Tokyo).
- 2012. Position: Visiting Researcher. Program: The Institutional Program for Young Researcher Overseas Visits at the University of Tokyo. Institution: The Warburg Institute, the University of London (UK). Project Title: Chinese Calendar in the Islamicate Astronomical Handbooks (Zījes). Supervisor: Charles BURNETT (the Warburg Institute).
- 2010–2011. Position: Visiting Fellow. Program: Excellent Young Researcher Overseas Visit Program at the Japan Society for the Promotion of Science (JSPS). Institution: Institute for the History of Science, the University of Tehran (Iran). Project Title: Chinese Calendar in the Islamicate Astronomical Handbooks (Zījes). Supervisor: Mohammad BAGHERI (the University of Tehran).
- 2009–2011. Position: Doctoral Fellow. Program: Research Fellowship for Young Scientists at the Japan Society for the Promotion of Science (JSPS). Institution: Graduate School of Arts and Sciences, the University of Tokyo. Project Title: Transmission of the Chinese Calendar into the Persianate World. Supervisor: HANEDA Masashi (the University of Tokyo).
- 2008–2009. Position: Doctoral Fellow. Program: Secularization, Religion, and the State. Institution: The University of Tokyo Center for Philosophy (UTCP). Project Title: Nourūz—Iranian New Year: the Secularization of the Ritual Time. Supervisor: HANEDA Masashi (the University of Tokyo).
- Yoichi Isahaya & 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.
- Yoichi Isahaya & Mitsuaki Endo, "Persian Transcription of Yuan Chinese in the History of China of the Jāmi‘ al-Tawārīkh (Ms. Istanbul, Topkapı Sarayı, Hazine 1654)," The Economic Review 経済研究 9 (2017): 123–161.
- Mitsuaki Endo & Yoichi Isahaya, "Yuan Phonology as Reflected in Persian Transcription in the Zīj-i Īlkhānī." The Economic Review 経済研究 8 (2016): 1–38.
- Yoichi Isahaya, “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).
- Yoichi Isahaya, “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.
- Yoichi Isahaya, “Gravity of Modernity: Reactions to the “New Astronomy” in Iran and Japan.” In Translation, History and Arts: New Horizons in Asian Interdisciplinary Humanities Research, edited by Ji Meng and Ukai Atsuko, pp. 27–47. Newcastle upon Tyne: Cambridge Scholars Publishing, 2013 [translated into Persian by Pouyan Rezvani in Miras-e Elmi-ye Eslam va Iran 2/2 (2014): 72–90].
- Yoichi Isahaya, “Vicissitudes of Nourūz: Islam, Zoroastrianism, and Historical Time Scales.” In Secularization, Religion and the States, edited by Haneda Masashi, 63–74. Tokyo: UTCP, 2010.
- Yoichi Isahaya, “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.
- Yoichi Isahaya, “Tarikh-i Khita wa Uyghur in Ulugh Beg's Zij: a Note on the Origin and Title of the Chinese Calendar Described in the Zij.” Mirzo Ulughbeg and His Contribution to the Development of the World Science (Proceedings of the International Scientific Conference), 169–177. Tashkent: “Fan” Publishing House, 2009.
- Yoichi Isahaya, “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).
Translations and Reviews
- Nasrollah Pourjavady, Yoichi Isahaya (trans.), "Izutsu's Interest in Iranian Mystical Philosophy." In Towards a Philosophy of Co-Existence: a Dialogue with Iran-Islam (2), Journal of International Philosophy, Extra Issue 7 (2016): 68–77.
- Yoichi Isahaya, "Review: Stephan Blake, Time in Early Modern Islam: Calendar, Ceremony and Chronology in the Safavid, Mughal, and Ottoman Empires." Nazariyat: Journal for the History of Islamic Philosophy and Sciences 2/3 (2015): 199–203 [Turkish version: Nazariyat İslâm Felsefe ve Bilim Tarihi Araştırmaları Dergisi 2/3 (2015): 193–197].
- Yoichi Isahaya, “Review: Hirotoshi Shimo, The Political Structure of the Mongol Empire.” Inner Asian Studies 29 (2014): 135–145 (in Japanese).
- Brian Spooner & William L. Hanaway, Yoichi Isahaya (trans.), “Siyaq: Numerical Notation and Numeracy in the Persianate World.” In The Oxford Handbook of the History of Mathematics, edited by Eleanor Robson & Jacqueline Stedall, trans.ed. by Ken Saito, Nobuo Miura & Katsuya Miyake, 383–401. Tokyo: Kyoritsu Shyuppan, 2014 (in Japanese).
- David Nicolle, Kazuhiro Shimizu (sup. trans.), Megumi Okamoto, Yoichi Isahaya, Norifumi Daito, Mutsumi Hamazaki (trans.), Historical Atlas of the Islamic World. Tokyo: Akashi Syoten, 2014 (in Japanese).
Oral Presentations (selected)
- Yoichi Isahaya, "Geometrizing Chinese Astronomy? The View from a Diagram in the Kashf al-Ḥaqā’iq by al-Nīsābūrī (d. ca. 1330)." International Conference "Traditional Sciences in Asia 2017: East-West Encounter in the Sciences of Heaven and Earth." Kyoto: Kyoto University, 26th October 2017.
- Yoichi Isahaya, "Fu Mengzhi: "The Sage of Cathay" in Mongol Iran and the Two-Way Exchange of Astral Sciences along the Silk Roads." International Conference "Cross-Cultural Contacts during the Period of Pax Mongolica." Seoul: Ewha Womans University, 23rd October 2017.
- Yoichi Isahaya, “Ilkhanid Translation Project: Toward Meso-History between Global and Local Perspectives.” International Medieval Congress 2017 “In Other Words: Redrawing Frameworks Using the ‘Global Middle Ages’ as Method, II.” Leeds: University of Leeds, 6th July 2017.
- Yoichi Isahaya, “Hülegüid Appanages: as Mesoscale Agency in Cross-Cultural Exchange.” International Workshop “Networks, Regions and Institutions in Mongol Eurasia: A Meso-Historical Analysis.” Jerusalem: The Hebrew University of Jerusalem, 18th May 2017.
- Yoichi Isahaya. “Sino-Iranica in Pax Mongolica: The Elusive Participation of Syriac-Rite Christians in the Ilkhanid Translation Project.” International Conference “Marco Polo and the Silk Road (10th–14th Centuries).” Beijing: Peking University, 20th November 2016.
- Yoichi Isahaya, "Regulating the Present, Prescribing the Future: Socio-Political Context of the Astronomical Dialogue in Mongol Eurasia."The 13th Biennial Conference of Asian Studies in Israel. Tel Hai: The Tel-Hai College, 19th May, 2016.
- Yoichi Isahaya, "Chinese Calendar in Persian under Mongol Domination: Two-Way Exchange of Astral Sciences across Eurasia." The Fifth Symposium on History of Astronomy. Tokyo: National Astronomical Observatory of Japan, 25th March, 2016.
- Yoichi Isahaya, "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 AD)." The Seminar Series of the ERC Project "Mobility, Empire and Cross Cultural Contacts in Mongol Eurasia" in 2015/16. Jerusalem: the Hebrew University (Israel), 25th November, 2015.
- Yoichi Isahaya, “Cross-Cultural Dialogue between a Chinese Sage and Muslim Polymath: Chinese Calendar in the Īlkhānīd Zīj as the Embodiment of the Astronomical Dialogue,” Mobility and Transformations: New Directions in the Study of the Mongol Empire (International Conference). Jerusalem: the Hebrew University (Israel), 1st July 2014.
- Yoichi Isahaya, “Reconsidering Spheres in the Celestial and Terrestrial Dimensions. The Qiyao rangzai jue, Fu tian li, and Their Application,” SAW Seminar 2013–2014: Astral Sciences in Context 1: Relations between Various Types of Sources, Variety of Milieus: “Theoretical Texts and Ephemerides.” Paris: Université Paris Diderot, Paris 7 (France), 23rd May 2014.
- Yoichi Isahaya, “ʿIlm al-Mīqāt and ʿIlm al-Hayʾa: the Role of Maragha in the Differentiation of Astronomy,” Maragha and its Scholars: The Intellectual Culture of Medieval Maragha, ca. 1250–1550. Istanbul: The German Oriental Institute (Turkey), 7th December 2013.
- Yoichi Isahaya, “The Mongol Impact on Astronomy: the Differentiation of Astronomy in the Eastern and Western Islamicate World.” World History for Current Issues (Environmental Issues, Globalization, and Conflicts): The Second Meeting of the McGill-Tokyo Collaboration. Tokyo: The University of Tokyo (Japan), 6th October, 2013.
- Yoichi Isahaya, “A Chinese Calendar in Persian: the Missing Link in Chinese Astronomy,” 24th International Congress of History of Science, Technology and Medicine: Astronomy and Its Applications in Western Asia and the Islamic World. Manchester: The University of Manchester (United Kingdom), 23rd July, 2013.
- Yoichi Isahaya, ““Sons of Heaven” underneath the Western Sky: Chinese Calendrical System in Persian during the Mongol Period,” Annual Conference of the Association for Asian Studies: Transmission of Scientific and Medical Knowledge in Asia: from the Mongol Empire to the Twentieth Century. San Diego: Manchester Grand Hyatt (America), 23rd March, 2013.
- Yoichi Isahaya, “Negotiating with Modernity: Transmission of ‘the History of Science’ into Nineteenth Century Iran,” The Second Congress of the Asian Association of World Historians: Transmission of Scientific Knowledge through Asia: Alternative Concepts and Methods. Seoul: Ewha Womans University (South Korea), 28th April, 2012.
- Yoichi Isahaya, “The Relationship between Astronomy and Society in Iran under the Mongol Domination: Toward the Social History of Science,” The Fifth Scientific Research Workshop in the Second Term in 1390. Tehran: Institute for the History of Science (Iran), 14th February, 2012 (in Persian).
- Yoichi Isahaya, “Gravity of Modernity: Reactions to the ‘New Astronomy’ in Japan and Iran,” Todai Forum: Local History in the Context of Global History. Lyon: ENS Lyon (France), 21th October, 2011.
- Yoichi Isahaya, “Chinese Terminology in ‘Persian’ Chinese Calendrical System,” Scientific and Philosophical Heritage of Nasir al-Din Tusi. Tehran: National Library of Iran (Iran), 24th February, 2011.
- Yoichi Isahaya, “Vicissitudes of Nourūz/New Year’s Festival in the Iranian Context,” Graduate Student Workshop on Secularization, Religion and the State. Singapore: National University of Singapore (Singapore), 21st January, 2010.
- Yoichi Isahaya, “Tarikh-i Khita wa Uyghur in Ulugh Beg’s Zij: a Note on the Origin and Title of the Chinese Calendar Described in the Zij,” Mirzo Ulughbeg and His Contribution to the Development of the World Science. Samarqand (Uzbekistan), 10th June, 2009.
- Yoichi Isahaya, “Migrating Time: the Transition of Time Conceptions by the Mongols across Thirteenth Century Eurasia,” UTCP Graduate Student Conference: The Plural Present of Historical Life. Tokyo: The University of Tokyo (Japan), 16th May, 2009.
- Yoichi Isahaya, “The Modification of the Twelve-Animal Cycle in the Timurid Period,” The Formation of Perso-Islamic Culture: The Mongol Period and Beyond. Tokyo: Tokyo University of Foreign Studies (Japan), 1st March, 2009.
Native language: Japanese.
Very good: Persian.
Reading skill: Arabic, Chinese, French, German, and Turkish.
Basic knowledge: Hebrew and Russian.