Sketch by Leonardo da Vinci, c. 1500
A crossbow is a weapon consisting of a bow
mounted on a stock that shoots projectiles,
often called bolts. The medieval crossbow
was called by many names, most of which de-
rived from the word Ballista, a siege engine
resembling a crossbow in mechanism and ap-
Crossbows played a significant role in the
warfare of North Africa, Europe and Asia.
They were developed in Ancient Greece and
East Asia with Ancient China being the main
source of archaeological evidence. The first
textual reference to crossbows were found in
the works of Mozi’s followers and Sun Tzu’s
The Art of War written in between 500 BC
and 300 BC and from the 2nd century BC
writer Biton referring to a 5th century work.
Crossbows are still being used in warfare.
However, they are used today primarily for
target shooting and hunting.
A crossbow is a bow mounted on a stick
(called a tiller or stock) with a mechanism in
it which holds the drawn bow string. The
earliest designs utilized a slot in the stock,
down into which the cocked string was
placed. To fire this design, a vertical rod is
thrust up through a hole in the bottom of the
notch, forcing the string out. This rod is usu-
ally attached perpendicular to a rear-facing
firing lever called a trigger or ’tickler’. A
later design utilized a rolling cylindrical pawl
called a ’nut’ to retain the cocked string. This
nut has a perpendicular center slot for the
bolt, and an intersecting axial slot for the
string, along with a lower face or slot against
which the internal trigger sits. They often
also have some form of strengthening intern-
al ’sear’ or trigger face, usually of metal.
These ’roller nuts’ were either free-floating in
their close-fitting hole across the stock, tied
in with a binding of sinew or other strong
cording, or mounted on a metal axle or pins.
Removable or integral plates of wood, ivory
or metal on the sides of the stock kept the
nut in place laterally. Nuts were made of
antler, bone, ivory or metal