Polyidus
2. Of Thessaly, a military engineer, who made improvements in the covered battering-ram (testudo arietaria) during Philip's siege of Byzantium, B. C. 340. His pupils were Diades and Chaereas, who served in the campaigns of Alexander. (Vitr. 10.19. s. 13.3, Schneider.)
From William Smith (ed.), Dictionary of Greek and Roman Biography and Mythology. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.