The Probert Encyclopaedia of Warfare

CROSSBOW

The crossbow (arbalist) is a bow fastened across a stock (hence the name
crossbow). The bow string was cocked and fired by way of a trigger, projecting a bolt. The crossbow was invented by the Normans but went out of fashion when the long-bow became popular, mainly because twelve arrows per minute could be fired from a long-bow compared to only three bolts per minute from a crossbow.
Research Crossbow