Marāgha Ceased to Function: The Ṭūsī Family’s Intellectual Network and Īl-Khānid Political Itinerance

While there is no consensus as to when the Marāgha observatory, centre of a Eurasian-scale intellectual network, ceased to function, given that no historical sources mention such a date, by focusing more on the Īl-Khānid political context than on the scientific activities at the observatory that have so far attracted scholarly attention, I argue that the termination of the observatory’s activity overlapped with the downfall of Aṣīl al-Dīn b. Naṣīr al-Dīn (d. ca. 1317) in 1309/10. Naṣīr al-Dīn al-Ṭūsī (1201–1274) acquired the office of trustee of the waqf endowments for the observatory. This office was inherited after his death by his sons. However, the family property related to the religious endowments was targeted, which resulted in the family’s fall. Thereafter, the eighth īl-khān, Öljeitü (r.1304–1316), did not station his mobile court in Marāgha, which marked a shift of the intellectual centre of the Īl-Khānid dynasty away from the observatory.