Zij-i Ilkhani - History

History

Hulagu Khan believed that many his military successes were due to the advice of astronomers (who were also astrologers), especially of al-Tusi. Therefore when al-Tusi complained that his astromical tables were 250 years old, Hulagu gave permission to build a new observatory in a place of al-Tusi's choice (he chose Maragheh). A number of other prominent astronomers worked with al-Tusi there, including Muhyi al-Din al-Maghribi, Qutb al-Din al-Shirazi, Mu'ayyid al-Din al-'Urdi from Damascus, and Hulagu's Chinese astronomer Fao Munji whose Chinese astronomical experience brought improvements to Ptolemaic system used by al-Tusi - traces of the Chinese system may be seen in Zij-i Ilkhani. The tables were published during the reign of Abaqa Khan, Hulagu's son, and named after the patron of the observatory. They were popular until the 15th century.

Some Islamic astronomical tables such as the Zij-i Al-`Ala'i of Abd-Al-Karim al-Fahhad and the Zij al-Sanjari of Khazini were translated into Byzantine Greek by Gregory Choniades and studied in the Byzantine Empire. Chioniades himself had studied under Shams ad-Din al-Bukhari, who had worked at the famous Maragheh observatory after the death of al-Tusi.