The tangzhuang is an adaption of the Manchu "horse jacket" (magua), a waist- or three-quarter-length front-opening jacket or surcoat.
This was initially worn—usually in a dark blue color—by Manchu horsemen, but became mandatory for Han officials' clothing under the Qing Empire.
Over time, it evolved from a protective apron for the changshan into an item of Chinese fashion in its own right and even a mark of imperial favor.
Its use then spread among the common Han, including among the Chinese diaspora abroad.

Following the 1911 Xinhai Revolution and 1949 Communist victory in the Chinese Civil War, the "Mao suit" (Zhōngshān zhuāng) gradually displaced the changshan and magua in most contexts.
After the fall of the Gang of Four in the late 1970s and the beginning of Deng Xiaoping's Opening Up Policy in the 1980s, traditional clothing began to experience a revival in mainland China.
Variants of the magua became noticeably more common in Chinese fashion from the mid-1990s.
The tangzhuang is an adaption of the Manchu "horse jacket" (magua), a waist- or three-quarter-length front-opening jacket or surcoat. This was initially worn—usually in a dark blue color—by Manchu horsemen, but became mandatory for Han officials' clothing under the Qing Empire. Over time, it evolved from a protective apron for the changshan into an item of Chinese fashion in its own right and even a mark of imperial favor. Its use then spread among the common Han, including among the Chinese diaspora abroad. 
Following the 1911 Xinhai Revolution and 1949 Communist victory in the Chinese Civil War, the "Mao suit" (Zhōngshān zhuāng) gradually displaced the changshan and magua in most contexts. After the fall of the Gang of Four in the late 1970s and the beginning of Deng Xiaoping's Opening Up Policy in the 1980s, traditional clothing began to experience a revival in mainland China. Variants of the magua became noticeably more common in Chinese fashion from the mid-1990s.
Tangzhuang