Diades of Pella was an ancient military engineer and one of Alexander the Great’s closest advisors, considered a true innovator in the field of war machines. While many aspects of his life remain a mystery, his contribution to the art of warfare is undeniable. Diades was from Pella, the capital of Macedonia, and probably trained under Polydus of Thessaly, one of the most respected engineers of the time.
Diades was responsible for the design and construction of the powerful war machines that enabled Alexander to capture key cities along his route of conquest. His inventions include: improved catapults that increased the range and effectiveness of missiles, and siege towers that allowed soldiers to storm the defensive walls. The most famous were his “helepolises” – mobile siege towers.
One of the most important moments in Diades’ career was the siege of the city of Tire in 332 BCE. The city, located on an island, was a key fortress and a strategic challenge. Diades designed a bridge there that allowed Alexander’s army to move its siege towers to the island. With the help of Diades’ machines, including huge catapults, the city was soon captured, which was one of the greatest achievements during the entire Asian campaign.
Diades’ engineering achievements are mentioned by Vitruvius.
[…] he was the inventor of ambulatory towers, which he caused to be carried from one place to another by the army, in pieces, as also of the auger and the scaling machine, by which one may step on to a wall; as also the grappling hook, which some call the crane (grus).
– Vitruvius, De architectura, X, 13, 3-4.
After Alexander’s death, Diades continued his engineering activities, but his fate remains unknown. Historians consider him one of the forerunners of military engineering and construction masters whose solutions were used by subsequent generations.
