Crossbows could shoot bolts just as far as longbows, but were impossible to reload as quickly. The concentration necessary, as well as the odd position the wielder had to bend into in order to draw back the bowstring (foot in the stirrup at the end, engaging a lever or crank, or using a claw strapped to the waist) left the crossbowmen open to attack. Hence the pavise, a large curved shield placed on the ground and able to stand on its own via props, provided a barrier that the crossbowmen could hide behind while reloading.
These shields ranged in size from 16 to 20 inches (42 to 45 cm) wide, and 22 to 42 inches (57 to 107 cm) high. The larger size weighed roughly 17 pounds (7569 g).
Pavises were first employed by the Genoese crossbowmen, the highly experienced professional soldiers from Genoa, Italy. Knights despised crossbows, as the bolts could pierce even the finest armor. So deadly were crossbows in fact, the Pope outlawed them at one time. Popular in the 14th and 15th centuries, pavises were carried on the backs of the crossbowmen, set down, then moved closer as the battle progressed. Often times, a second man, called a paviser, moved the shield, freeing the crossbowman of the burden. Thus, these shields were large enough to protect one to three men, protecting them as they took turns hiding and firing. An ingenious invention, provided that the pavises were not stuck on the baggage wagons like they were at the Battle of Crecy (1346), where, unprotected, the Genoese crossbowmen took a beating first from the opposing English army, and then from the French nobles who had recruited them.