Hero of Byzantium is believed to be the literary pseudonym of an otherwise anonymous Byzantine author of a poliorketikon, an illustrated manual of siegecraft, dating from circa 950. He is also credited with the Geodaesia, a work in practical geometry and ballistics which makes use of locations around Constantinople to illustrate its points.

His Poliorketikon was an adaptation of an earlier (c. 100) poliorcetic manual of Apollodorus, but in place of the static two-dimensional diagrams of that work, the Byzantine author has used a three-dimensional perspective and scaled human figures to clarify the passages. Further, there are passages or techniques from Athenaeus Mechanicus, Philo of Byzantium and Biton. The translated manuscript in the Vatican Library consists of 58 folios and 38 colored illustrations.

As artillery had not yet become a factor in siegecraft, the machines themselves tend to be those useful for advancing a force up to fortifications and undermining them once situated (see sapping). Hero includes tortoises (Gr. Χηλοναι), a new Slavic style of tortoise called laisai (Gr. λαισαι) created by interwoven branches and vines, palisades, rams, ladders, nets, towers, bridges, and tools such as augurs and bores.

Sources

"Byzantine Siege Warfare in Theory and Practice" by Eric McGeer from The Medieval City under Siege

Medieval Warfare in Manuscripts by Pamela Porter.