It included data derived from the observations made over the course of 12 years in the Maragha observatory, completed in 1272.
AD), were so faulty that later astronomers, such as al-Wabkanawi and Rukn al-Din al-Amuli, criticized it severely.
Hulagu Khan believed that many of his military successes were due to the advice of astronomers (who were also astrologers), especially of al-Tusi.
The tables were published during the reign of Abaqa Khan, Hulagu's son, and named after the patron of the observatory.
Chioniades himself had studied under Shams ad-Din al-Bukhari, who had worked at the famous Maragheh observatory after the death of al-Tusi.