Dionysius I of Syracuse
According to a long dominant view expressed by E. W. Marsden, the gastraphetes was invented in 399 BC by a team of Greek craftsmen assembled by the tyrant Dionysius I of Syracuse. However, recent scholarship has pointed out that the historian Diodorus Siculus (fl. 1st century BC) actually did not mention the gastraphetes, but was referring to the invention of the "katapeltikon", a mechanical arrow firing catapult. Since Heron states in his "Belopoeica" that stand-mounted mechanical artillery such as the "katapeltikon" was inspired by the earlier hand-held gastraphetes, the invention of handheld crossbows into Greek warfare must have thus occurred some unknown time before 399 BC.