Tusi Persuades Hulagu, and the Zij-i Ilkhani Follows

This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.

The Maragheh Observatory was built in 1259 in northwestern Iran under the patronage of the Mongol Ilkhanid ruler Hulagu and directed by the Persian polymath Nasir al-Din al-Tusi, who had persuaded Hulagu that his astronomical tables needed a purpose built institution rather than being compiled without one. The observatory drew astronomers from across the Islamic world and beyond, gathering the instruments, library and working scholarly community a project of that scale required in a single location for the first time in the region.

Its scholars produced the Zij-i Ilkhani, an astronomical tables compilation whose mathematical innovations were later used by the astronomer Ibn al-Shatir and, some historians argue, transmitted onward to Nicolaus Copernicus, making Maragheh's own working methods part of a chain of influence some scholars trace directly into the European Copernican revolution nearly three centuries later. That claimed transmission remains debated among historians of science, but the observatory's own technical output, the Zij-i Ilkhani itself, is not in dispute, and the tables were consulted by astronomers across the Islamic world for generations after they were first compiled at Maragheh under Tusi's own direction.