is a category of single-edge swords primarily used for slashing and chopping , often called a ''broadsword'' in translation because some varieties have wide blades. In China, the dao is known as one of the four major weapons, along with the ''Gun '', ''Qiang '', and the '''', and referred to as "The General of All Weapons". Dao is actually a generic word used to denote any member of a family of , broad-bladed cutting or slicing tools, but in common, everyday usage means knife. The weapon, also known as ''dan dao'' when just one is used, is thereby thought to be an adaptation of the kitchen knives common to Chinese cuisine. ''Dao'' also appears in the names of such as the ''pudao'' and ''guan dao'', indicating the knifelike nature of their blades.
While dao have varied greatly over the centuries, most single-handed dao of the period and later, and the modern swords that are based on them share a number of characteristics. Dao blades are moderately curved and single-edged, though often with few inches of the back edge sharpened as well; the moderate curve allows them to be reasonably effective in the thrust. Hilts are canted, curving in the opposite direction as the blade which improves handling in some forms of cuts and thrusts. Cord is usually wrapped over the wood of the handle. Hilts may also be pierced like those of ''jian'' for the addition of lanyards, though modern swords for performances will often have tassels or scarves instead. Guards are typically disc-shaped often with a cupped shape to prevent rainwater from getting into the sheath, and to prevent blood from dripping down to the handle, making it more difficult to grip. Sometimes guards are thinner pieces of metal with an s-curve, the lower limb of the curve protecting the user's knuckles; very rarely they may have guards like those of the ''jian''.
Other variations to the basic pattern include the large '''' and the long handled ''pudao''.
The earliest dao date from the Shang Dynasty in China's Bronze Age, and are known as ''zhibei dao'' - straight backed knives. As the name implies, these were straight-bladed or slightly curved weapons with a single edge. Originally bronze, these would be made of iron or steel by the time of the late Warring States. Originally less common as a military weapon than the jian - the straight, double-edged blade of China - the dao became popular with cavalry during the Han dynasty due to its sturdiness and superiority as a chopping weapon. Soon after dao began to be issued to infantry, beginning the replacement of the jian as a standard-issue weapon.
During the Tang Dynasty, dao were exported to both Korea and Japan, influencing the swordsmithing of both nations. The blades of Tang era dao are reminiscent of the Japanese chokuto or the popular image of the quasi-mythical ninjato.
During the Song Dynasty, one form of infantry dao was the ''shoudao'', a chopping weapon with a clip point. While some illustrations show them as straight, the 11th century Song military encyclopedia ''Wujing Zongyao'' depicts them with curved blades - possibly an influence from the steppe tribes of Central Asia, who would conquer parts of China during the Song period. Also dating from the Song are the falchion-like ''dadao'' and the long, two-handed ''zhanmadao''.
Yuan, Ming and Qing
The Mongols invaded in the early 13th century in the process of conquering the largest land empire in history. The Yuan dynasty of the Mongols influenced China and other nations considerably, particularly in the tools and tactics of war. A favored weapon of the Mongol cavalry was the sabre: this simple, one handed, curved blade had been used by the and Tungusic tribes of Central Asia since the 8th century at least. Its effectiveness for mounted warfare and popularity among soldiers across the entirety of the Mongol empire had lasting effects. The Persian shamshir, the Indian talwar, the Afghani pulwar, the Turkish kilij, the Arabian saif, the Mamluk "scimitar", and the European sabre and cutlass are perhaps descended from the Turko-Mongol curved blade.
In China, Mongol influence lasted long after the collapse of the Yuan dynasty at the hands of the , continuing through both the Ming and the dynasties , furthering the popularity of the dao and spawning a variety of new blades. Blades with greater curvature became popular, and these new styles are collectively referred to as ''pei dao''. During the mid-Ming these new sabers would completely replace the ''jian'' as a military-issue weapon. The four main types of ''pei dao'' are:
* ''yanmao dao'', or "goose-quill sabre." This weapon, similar to the earlier ''zhibei dao'', is largely straight, with a curve appearing at the center of percussion near the blade's tip. This allows for thrusting attacks and overall handling similar to that of the ''jian'', while still preserving much of the dao's strengths in cutting and slashing.
* ''liuye dao'', the "willow leaf saber." The most common form of Chinese sabre, this weapon features a moderate curve along the length of the blade. This weapon became the standard sidearm for both cavalry and infantry, and is the sort of sabre originally used by many schools of Chinese martial arts.
* ''pian dao'', "slashing sabre." A deeply curved dao meant for slashing and draw-cutting, this weapon bears a strong resemblance to the shamshir and scimitar. A fairly uncommon weapon, it was generally used by skirmishers in conjunction with a shield.
* ''niuweidao'', the "oxtail sabre." A heavy bladed weapon with a characteristic flaring tip, this is the archetypal "Chinese broadsword" of kung fu movies today.
Besides these four types of dao, the ''duan dao'' or "short dao" was also used, this being a compact weapon generally in the shape of a ''liuye dao''. The ''dadao'' saw continued use, and during the Ming dynasty the large two-handed '''' and ''zhanmadao'' were used both against the cavalry of the northern steppes and the pirates of the southeast coast; these latter weapons would continue to see limited use during the Qing period. Also during the Qing there appear weapons such as the ''nandao'', regional variants in name or shape of some of the above dao, and more obscure variants such as the "nine ringed broadsword," which were likely invented for street demonstrations and theatrical performances rather than for use as weapons.
The Chinese and dao were commonly issued to infantry due to the expense of and relatively greater amount of training required for the effective use of Chinese straight sword, or ''jian''. Dao can often be seen depicted in period artwork worn by officers and infantry.
During the Yuan dynasty and after, some aesthetic features of Persian, Indian, and swords would appear on dao. These could include intricate carvings on the blade and "rolling pearls": small metal balls that would roll along -like grooves in the blade.
Some of the blades from the Qing Dynasty lived on and even had descendants see military action in the 20th century. The ''dadao'' was used by some Chinese militia units against Japanese invaders in the Second Sino-Japanese War, as was the ''miao dao'', a descendant of the ''''. These were used during planned ambushes on Japanese troops because the Chinese military and patriotic resistance groups often had more willing soldiers than firearms.
Most Chinese martial arts schools still train extensively with the dao, seeing it as a powerful conditioning tool and a versatile weapon, with self defense techniques transferable to similarly sized objects more commonly found in the modern world, such as canes, baseball or cricket bats, for example. There are also schools that teach double broadsword ''shuang dao'' , forms and fencing, one Dao for each hand.
One measure of the proper length of the sword should be from the hilt in your hand and the tip of the blade at the brow and in some schools, the height of shoulder. Alternatively, the length of the sword should be from the middle of the throat along the length of the outstretched arm. There are also significantly larger versions of dao used for training in some Baguazhang and Taijiquan schools.