A catapult is any one of a number of non-handheld mechanical devices used to throw a projectile a great distance without the aid of an explosive substance—particularly various types of ancient and medieval siege engines.

The name is the Latinized form of the Ancient Greek hiκαταπέλτης - katapeltes, from κατά - kata (downwards, into, against) and πάλλω - pallo (to poise or sway a missile before it is thrown). The catapult appears to have been invented in 399 BC in the city of Syracuse during the reign of the tyrant Dionysius I. Originally, "catapult" referred to a dart-thrower, while "ballista" referred to a stone-thrower, but the two terms swapped meaning sometime in the fourth century AD.Fact: date=November 2007

Greek and Roman catapults

The early history of the catapult and the crossbow in Greece is closely intertwined. The historian Diodorus Siculus (fl. 1st century BC), described the invention of a mechanical arrow firing catapult (katapeltikon) by a Greek task force in 399 BC.Duncan Campbell: Greek and Roman Artillery 399 BC-AD 363, Osprey Publishing, Oxford 2003, ISBN 1841766348, p.3 The weapon was soon after employed against Motya (397 BC), a key Carthaginian stronghold in Sicily.Duncan Campbell: Greek and Roman Artillery 399 BC-AD 363, Osprey Publishing, Oxford 2003, ISBN 1841766348, p.8 Diodorus is assumed to have drawn his description from the highly rated history of Philistus, a contemporary of the events then. The date of the introduction of crossbows, however, can be dated further back: According to the inventor Hero of Alexandria (fl. 1st c. AD), who referred to the now lost works of the 3rd century BC engineer Ctesibius, this weapon was inspired by an earlier hand-held crossbow, called the gastraphetes (belly shooter), which could store more energy than the Greek bows. A detailed description of the gastraphetes, along with a drawing, is found in Heron's technical treatise Belopoeica.Duncan Campbell: Greek and Roman Artillery 399 BC-AD 363, Osprey Publishing, Oxford 2003, ISBN 1841766348, p.4 A third Greek author, Biton (fl. 2nd c. BC), whose reliability has been positively reevaluated by recent scholarship, described two advanced forms of the gastraphetes, which he credits to Zopyros, an engineer from southern Italy. Zopyrus has been plausibly equated with a Pythagorean of that name who seems to have flourished in the late 5th century BC. He probably designed his bow-machines on the occasion of the sieges of Cumae and Milet between 421 BC and 401 BC.Duncan Campbell: Greek and Roman Artillery 399 BC-AD 363, Osprey Publishing, Oxford 2003, ISBN 1841766348, p.5 The bows of these machines already featured a winched pull back system and could apparently throw two missiles at once.