Diades of Pella ( Diadis Pelleos), surnamed the "Besieger" ( Poliorkitis), was a Thessalian inventor of many siege engines, student of Philip II's military engineer Polyidus of Thessaly. He lived in the 4th century BC. Diades accompanied Alexander the Great in his campaigns to the East. He constructed (or improved) movable towers, battering rams, scaling engines used to scale walls and battering cranes used for the destruction of city walls. Diades was known as "the man who took Tyre with Alexander". He also wrote a treatise on machinery. (Vitruvius vii, introduction) Notes External links Technology museum of Thessalonica Ancient Greek military engineers Engineers of Alexander the Great Ancient Greek engineers Ancient Thessalians Ancient Pellaeans Hellenistic military engineers 4th-century BC Greek people Year of death unknown Year of birth unknown