 He believed it was the forerunner of the catapult, which places its appearance sometime prior to the 4th century BC.Other than the gastraphetes, the only other evidence of crossbows in ancient Europe are two stone relief carvings from a Roman grave in Gaul and some vague references by Vegetius.Pictish imagery dated between the 6th and 9th centuries AD do show what appear to be crossbows, but only for hunting, and not military usage.