Nasir al-Din Tusi builds the Maragheh observatory

1256

Under Hulagu's patronage, the Persian polymath Nasir al-Din Tusi established an astronomical observatory at Maragheh in Azerbaijan, equipped with massive instruments and a library of four hundred thousand volumes. His planetary models, correcting Ptolemy, would influence Copernicus two centuries later through channels still debated by historians. The observatory attracted scholars from China, Byzantium, and the Islamic west, making it history's first international research institution.