Po Dao (朴刀)

An ornate Po Dao once belonged to Taiping general Luo Da Gang (羅大綱). Private Collection.

Po Dao is a type of Chinese sword or glaive with a cleaving blade that usually ends in a very steep clip point. Po Dao comes in one-handed, two-handed, equal handle to blade ratio, polearm and even a "bifurcated weapon" form, although the term generally refers to polearm version in common usage. It should be noted that the weapon's name is written as "朴刀", even in traditional Chinese. It cannot be written as "樸刀".

Humble Origin

The weapon known as Po Dao first appeared during Song Dynasty. At the time it was also known as Po Dao (潑刀), Bō Dao (撥刀), Bó Dao (博刀 or 膊刀) and many other names. Essentially a weaponised agricultural tool, Po Dao was not considered a "military grade" regulation weapon and commonly found in the hands of militias, bandits, outlaws and rebels alike (and thus enjoyed unusually high exposure in literature, dramas and plays, which tend to portray civilian rather than military life).

Horse Chopper

A Po Dao (highlighted), also known as Zhan Ma Dao, from 'Wu Bei Yao Lue (《武備要略》)'.

It is not known exactly when, or why, long-handled Po Dao came to be known as Zhan Ma Dao (斬馬刀), although this may be related to Song general and Chinese national folk hero Yue Fei (岳飛) and his elite army, the Yue Jia Jun (岳家軍, lit. 'Army of House Yue'). Yue Fei and his army famously wielded a weapon known as Ma Zha Dao (麻紥刀, lit. 'Linen-wrapped knife') to chop at vulnerable horse legs of the otherwise heavily armoured Jurchen cataphracts. While the length and form of Ma Zha Dao had been lost to the passage of time (although it is almost certainly a two-handed chopping polearm, a.l.a. Po Dao), Yue Fei's legendary exploits had profound influence on later Chinese military thinking. By Ming period, weapons such as Ma Zha Da Kang Dao (麻紥大砍刀, lit. 'Linen-wrapped great chopping sabre') and Ma Zha Zhan Ma Dao (麻紮斬馬刀, lit. 'Linen-wrapped horse-chopping sabre') started to show up in Ming arsenal records, alongside regular Zhan Ma Dao. Polearm/glaive type Zhan Ma Dao also replaced Song period two-handed swords as the most ubiquitous horse chopper.

Although Zhan Ma Dao had become a more recognisable name for Po Dao during Ming period, some Ming texts, such as the writings of general Yu Da You (俞大猷), still referred the weapon with its old name.

Cheng Zi Yi's modified Po Dao

Cheng Zi Yi's modified Po Dao and scabbard, from 'Wu Bei Yao Lue (《武備要略》)'.

Late Ming period military writer Cheng Zi Yi (程子頤) designed a two-handed sword version of Po Dao in order to make the weapon more compatible with Dan Dao Fa Xuan (單刀法選) techniques. By doing so, he effectively combined two types of Zhan Ma Dao (Type B and Type C) into one weapon.

The new weapon features ridged cross-section and resembles both a Dan Dao (單刀) and a Song period Zhan Ma Dao.

Qing Dynasty Po Dao

Different types of Qing Dynasty Po Dao. Top left: Lu Ying Pu Dao. Top mid: Lu Ying Kuan Ren Pian Dao. Top right: Lu Ying Kuan Ren Da Dao. Bottom left: Lu Ying Chuan Wei Dao. Bottom mid: Lu Ying Hu Ya Dao. Bottom right: Tiao Dao. Images taken from 'Qin Ding Da Qing Hui Dian Tu 《欽定大清會典圖》' and 'Huang Chao Li Qi Tu Shi (《皇朝禮器圖式》)'.

After the fall of Ming, many elements of former Ming military were absorbed into Qing military system and reorganised into either Lu Ying (綠營, Green Standard Army) or Han Jun (漢軍, lit. 'Han army', ethnic Han bannermen). These Han Chinese soldiers retained most of their traditional weapons and equipment, only minimally modified to adapt to the new military regulation.

Under Qing military regulation, Po Dao was divided into several subtypes based on their length and blade profile:

• Lu Ying Pu Dao (綠營撲刀, lit. 'Green Standard Army Pu Dao') is a rather short, one-handed version of Po Dao.
• Lu Ying Kuan Ren Pian Dao (綠營寬刃㓲刀, lit. 'Green Standard Army broad bladed slicing sabre') is a Po Dao with a handle of about equal length to its blade.
• Lu Ying Kuan Ren Da Dao (綠營寬刃大刀, lit. 'Green Standard Army broad bladed great glaive') is a standard polearm-length Po Dao.
• Lu Ying Chuan Wei Dao (綠營船尾刀, lit. 'Green Standard Army stern sabre') is named due to the blade shape's similarity to the stern of a ship. It is a two-handed sword that has a longer and sharpened clip point tip for better thrusting capability. 
• Lu Ying Hu Ya Dao (綠營虎牙刀, lit. 'Green Standard Army tiger tooth sabre') is a larger version of Chuan Wei Dao that has a roughly equal ratio of handle length to blade length.
• Teng Pai Ying Tiao Dao (藤牌營挑刀, lit. 'Rattan Shield Regiment lifting glaive') is a polearm-length version of Chuan Wei Dao with narrower blade. Unlike other weapons in this list, this weapon was issued to Han Bannermen that specialised in rattan shield tactics.

Late Qing period Shuang Shou Dai (雙手帶) and Tai Ping Dao (太平刀)

Mid-nineteenth century export painting depicting a militiaman armed with a Shuang Shou Dai. From Digital Collections of the New York Public Library. (Source: Kung Fu Tea)

As the once great Qing Empire aged and corruption began to run rampant, its hereditary military system also weakened and eventually collapsed. Militias and levies replaced professional soldiers as the main source of recruit, and brought with them many non-regulation weapons. Po Dao, which has its root in agricultural tool and civilian weapon, once again became one of the most common close combat weapons of the Qing army.

Late Qing period Po Dao are generally short polearms with roughly equal length handle and blade. As old regulations and names fall into disuse, these short polearms came to be known as Shuang Shou Dai (雙手帶, lit. 'Double hand carry'), even though the term originally referred to a type of two-handed sabre. After Taiping Rebellion broke out, this weapon gained yet another moniker "Tai Ping Dao (太平刀, lit. 'Taiping sabre')" due to its prevalence among Taiping rebels.

Republican Long handled Da Dao (大刀) 

Chinese soldiers during the Second Sino-Japanese War, armed with Shuang Shou Dai-type Da Dao.

Throughout the entire Second Sino-Japanese War, Chinese forces often found themselves severely underequipped and had to outfit their soldiers with all sort of sabres, cleavers, and glaives. With little standardisation going on, these weapons were lumped together and collectively called Da Dao (大刀, lit. 'Great sabre') or sometimes Kan Dao (砍刀, lit. 'Chopping sabre') regardless of their length, shape and size. Some Shuang Shou Dai also saw service in the war as Da Dao, and techniques of Shuang Shou Dai became the basis of Da Dao drills.