ARQUEBUS (also called harquebus, hackbut, etc.), a firearm of the 16th century, the immediate predecessor of the musket. The word itself is certainly to be derived from the German Hakenbühse (mod. Hakenbüchse, cf. Eng. hackbut and hackbush), "hook gun." The "hook" is often supposed to refer to the bent shape of the butt, which differentiated it from the straight-stocked hand gun, but it has also been suggested that the original arquebus had a metal hook near the muzzle, which was used to grip the wall (or other fixed object) so as to steady the aim and take up the force of recoil, that from this the name Hakenbühse spread till it became the generic name for small arms, and that the original form of the weapon then took the name of arquebus à croc. The French form arquebuse and Italian arcobugio, archibugio, often and wrongly supposed to indicate the hackbut's affinity with the crossbow ("hollow bow" or "mouthed bow"), are popular corruptions, the Italian being apparently the earlier of the two and supplanting the first and purest French form haquebut. Previous to the French wars in Italy, hand-gun men and even arbalisters seem to have been called arquebusiers, but in the course of these wars the arquebus or hackbut came into prominence as a distinct type of weapon. The Spanish arquebusiers, who used it with the greatest effect in the Italian wars, notably at Bicocca (1522) and Pavia (1525), are the originators of modern infantry fire action. Filippo Strozzi made many improvements in the arquebus about 1530, and his weapons were effective up to four and five hundred paces. He also standardized the calibres of the arquebuses of the French army, and from this characteristic feature of the improved weapon arose the English term "caliver." In the latter part of the 16th century (c. 1570) the arquebus began to be displaced by the musket.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)