The story goes that when one of his students[10] was captured during the Byzantine–Arab Wars, the Caliph al-Mamun was so impressed by his knowledge of mathematics, providing proofs that his own scholars were unable to complete, and predictive abilities that he offered Leo great riches to come to Baghdad.
[11] Leo took the letter from the caliph to the Byzantine emperor Theophilos, who, impressed by his international repute, conferred on him a school (ekpaideutērion) in either the Magnaura or the church of the Forty Martyrs.
Al-Mamun then offered two thousands pounds of gold and a perpetual peace to Theophilos, if only he could borrow Leo's services briefly; the request was declined.
[16] He was renowned for his philosophical, mathematical, medical, scientific, literary, philological, seismological, astronomic, and astrological learning, and was patronised by Theoktistos and befriended by Photios I of Constantinople.
Leo has been credited with a system of beacons (an optical telegraph) stretching across Asia Minor from Cilicia to Constantinople, which gave advance warning of Arab raids, as well as diplomatic communication.
He wrote book-length works, poems, and many epigrams,[22] and was also a compiler, who brought together a wide range of philosophical, medical, and astronomic texts.