Yari (槍) is the Japanese term for the spear, more specifically the straight-bladed spear. The martial art of mastering the yari is known as sōjutsu.
The yari could measure from one meter to 6, with the longer ones being known as ōmi no yari while the shorter ones as "mochi" or "tae yari".
The longer versions were wielded by the ashigaru who served as foot troops while the samurai usually used the shorter versions.
Believed to have been derived from Chinese spears, these hoko yari are believed to have belonged to the Nara period (710-794), and were present in early Japanese history.
The term yari first appeared in written sources in 1334, but this type of spear became popular until the late 15th century. The original bushi warfare was not something for commoners, it was a ritualized combat usually between two warriors who would challenge each other through horseback archery.
However, the attempted Mongol invasion of Japan between 1274 and 1281 changed Japanese weaponry and their way of warfare. The Mongols employed Chinese and Korean footmen wielding long pikes, who fought in tight formations and moved in large units to avoid cavalry.
Spears were preferred, including naginata and yari, which were more efficient from a military perspective than swords due to their significantly longer reach, lighter weight per unit length (although in general a spear would be quite strong), and their great piercing ability.
Swords in a battle situation were therefore relegated to emergency situations as a secondary weapon from the Heian period through the Muromachi.
Around the second half of the 16th century, ashigaru armed with pikes (nagae yari) of a length of 4.5 to 6.5 m became the main forces in the armies of Japan.
They formed lines, combined with soldiers carrying firearms (tanegashima) and short spears. The pikemen formed a line of two or three ranks and were trained to move their pikes simultaneously under command.
The yari gradually became more popular than the longbow as a weapon for the samurai, so the foot troops or ashigaru followed suit and used them extensively.
With the advent of the Edo period the yari fell into disuse, greater emphasis was placed on small-scale close combat. Hence the desirability of swords as opposed to long weapons on the battlefield; polearms and the bow lost their practical value.
During the peaceful Edo era yari were still produced (sometimes made by renowned gunsmiths), although they existed mainly as a ceremonial weapon or for exclusive use by the police.
The yari was characterized by having a straight blade that could be several centimeters to a meter or more in length. The blades were made of the same steel (tamahagane) from which traditional Japanese swords as well as arrowheads were forged and were very durable.
Throughout history many variations of the straight yari blade were produced, often with protrusions above the center blade. Yari blades often had an extremely long tang (nakago), which would generally be longer than the sharpened portion of the blade.
The tang was inserted into the hollow of the handle which was reinforced (tachiuchi or tachiuke), resulting in a very rigid shaft that makes it almost impossible for the blade to fall or break.
The shaft (nagaye or ebu) appeared in different lengths, widths and shapes; it was made of hardwood and covered with lacquered bamboo strips. Its cross-section was oval, round or polygonal, which was often wrapped with metal rings or wire (dogane), and fixed with a metal knob (ishizuki) at the terminal end.
The yari shafts were often decorated with inlays of metal or semi-precious materials, such as brass nails, lacquer or pearl flakes. A sheath or sheath (saya) was also part of a complete yari.
A yari shaft could vary in length from one meter to over six meters.