Ku (trousers)

Ku or , collectively refers to the traditional Chinese trousers in  in the broad sense. can also refer to the,  which are Chinese trousers without a rise as opposed to the trousers with a rise, referred as   or   in ancient times.

The upper garment, the which evolved from the  which existed since the neolithic period, and the   from which the   eventually evolved from, are indigenous to Central area of China. When the is combined with the  upper garment and the, the complete attire in the -system is formed. The is worn as a lower garment in a set of attire known as  and/or sometimes be worn under the skirt of the. With time, the Chinese trousers evolved and changed in a variety of shapes and styles. The adoption of the used in the  of Northern nomadic people through the adoption of the  policy by King Wuling of Zhao during the Warring States period eventually made the -style trousers popular among the ancestors of the Han Chinese and the Chinese ethnic minorities in the South. The -style influenced the development of both the  and  of the Han Chinese and the  of the other ethnic minorities of China leading to the creation and development of more innovative styles of trousers with time. There are many different styles and shapes of which differ based on the ethnic groups of China; the shape and form of the rise structure in the  also vary depending on different ethnic minorities.

Terminology
As a general term, the term  and   can both be literally translated as "trousers or pants" in English language. The Chinese character for (褲) has other character variants such as  and. The character  is the archaic form of character of. The term  refers to shorts.

/
The were referred as   in the Warring States period. In a Qin dynasty manuscript called 《制衣》(lit. 'Making Clothes'), however, Chinese trousers, including, are recorded as

/
The, as the earliest form of trousers consisting of two separate legs for each leg, also became known as  ,  ,  , and   through different period of time.

In the Shang dynasty, the term  could be used as a general term to refer to both the  and the skirt called. In the Spring and Autumn period and Han dynasty, trousers without crotches were called. The term  can also be found in the ancient texts, such as in the Western Han dynasty text called  《方言 》by Yang Xiong, and in the chapter 《小爾雅》of the   dating from the Eastern Han to Three Kingdoms period. According to the, the , which was in Guangxi, was also called《》or《》in.

Pre-Warring States period
The was worn in China since the neolithic times, where it was called. The was the earliest form of in China and only covered the shank of its wearer. The consisted of two separated legs which were tied on calves and allowed to exposure of the thighs. As a result, a wrap-skirt had to be worn to hide the lower body and the crotch area. The was also used to protect its wearer from the cold and to protect its wearer's skin. In the Spring and Autumn period, trousers without crotches were still in use.

Warring States period, Qin dynasty
The Warring States period marks the beginning of the history of through the  policy adopted by King Wuling of Zhao. The with a loose rise was a form of, which were originally worn by the Northern nomadic peoples. Through the policy, the -style  with loose rise was introduced in Central China and first adopted and used by the military troops before eventually being used by the general populations in the succeeding dynasties. Under the influence of the -style with loose rise, the Chinese-style, referred as  , was developed. The -style also influenced the -style  leading to the lengthening of the  to the thigh and to the development of a waist enclosure with an open rise and rear which allowed for urination and defecation, thus forming the basic form of  as trousers with open rise. Since the rear and the rise of the trousers were both opened, a skirt continued to be worn to hide the genitals. An example of a typical form of trousers is the embroidered silk brocade  discovered in the  Chu tomb in Jiangling, Hubei province.

In a Qin dynasty manuscript called, however, the term  could also be used to refer to the  while the rise of the trousers itself was referred as. While new forms of trousers were developed, the -style  continued to be worn until the early Han dynasty.

Han dynasty
There were variety of trousers in the Han dynasty, including full trousers with tampered cuffs. The attire was worn by men in ordinary times.

In this period, the developed into new styles of Chinese trousers, such as   which were trousers with extremely wide legs and the , which was a type of trousers which were tied with strings under the knees in this period. The however was rarely used by the general population and were only used by warriors and servants during this period as the members of the high society were still deeply influenced by the traditional etiquette of the Han culture and found the  disgraceful for allowing the exposure of its wearer's leg shape; moreover, people had difficulty adjusting to the use of the  in their everyday lifestyle and routines as they were used to their traditional. In the chapter 《急就篇》by Shi You during the Western Han dynasty, the  consisted of the , a wide-legged  which were bound with strings at the around the knees, and was worn with a tight knee-length   robe.

Compared to the, the was more acceptable in the Han tradition and became an important form of garment attire item in. A typical form of in the Han dynasty had two complete legs connected to the waist with a piece of fabric which would cover the abdomen but leave the hips uncovered; an example of this form of  can be found in the Mawangdui Han tomb at Changsha, Hunan Province; compared to the, this form of  had a closed front rise and an open rear. In the Western Han dynasty, another form of, called , was designed for the maids living in the palace and was also worn in the imperial court. The was characterized with an upper part which covered the hip regions and a lower part which covered the lower legs; the rise and the waist of the  is closed at the front and multiple strings were used to tie it at the back. According to the Biography of Queen Shangguan in the History of the Han dynasty, the was exclusively designed for the imperial concubines who were then forced to wear it; the reason behind it was to help queen Shangguan to monopolize the favour of Emperor Zhao Di and to produce an heir; the use of  would therefore prevent Emperor Zhao Di from having sexual activities with other imperial concubines.

Wei, Jin, Northern and Southern dynasties
In the early Six dynasties period, the trousers which were worn by commoners were similar to those worn in the Han dynasty having full legs with tapered cuffs. Male commoners continued to wore it in their while female commoners could either wore it in their  or under their. In the Jin dynasty, clothing did not change much and trousers were worn by servants and people with low status.

During the Wei, Jin, Northern and Southern dynasties, the (especially the wide-bottomed ) became a common form of  amongst the nobles and the commoners. This style of knee-bound was also known as. By binding the trousers below the knees, the would facilitate movements,  including when horseback riding or when men were on duty. The chord used to bind the knees were made out of felt in the Western Jin; however, as the use of felt was a product of the Eurasian steppes; it was assumed to be by the contemporary observers of this period. In fact, while the was designed under the influence of the ancient -style, it was a Chinese innovation and was not a form of. In the Northern Wei, some women started to wear instead of skirts under the influence of the northern nomads. When the was matched with a tight knee-length upper garment, it formed the, which then became both the military and official attire in both the north and south of China at those times. The was a popular form of attire until the Sui and Tang dynasties.

Sui and Tang dynasties
In the Tang dynasty, the were only used by warriors and the guards of honour. The became popular amongst women who wore it under their skirt. New form of trousers then appeared with narrow legs instead of loose legs.

Song dynasty and Yuan dynasty
Trousers with narrow legs, called, were worn by the general population.

The  (), a -style, first appeared in the Song dynasty. It became so popular that it was occasionally worn by the Emperors. The  remained popular in the Yuan dynasty. A style of ' was called '; however, the wearing of  was forbidden for noble ladies and only actresses were allowed to wear them when performing in drama theatres.

Ming dynasty
In the Ming dynasty,  evolved into another -style called  ; the  however had to be worn over other forms of trousers. Trousers continued to be worn by both genders either under the ' or skirt of the '.

Ethnic clothing
The -style remains popular among minority ethnicities, such as the Hani and the Miao women; they are now referred as.

Derivatives and influences

 * Chinese-style trousers were adopted in the precursor of the áo dài in during the Nguyễn dynasty in Vietnam.
 * Chinese-style trousers were adopted in the precursor of the áo dài in during the Nguyễn dynasty in Vietnam.