The United Bamboo Gang (UBG), also known as the Bamboo Union, is the largest of Taiwan's three main triad gangs. The triad was founded in the 1950s by mainland Chinese immigrant children who wanted to protect themselves from threats by Taiwanese children, and the gang gained recognition in society through street fighting. By the late 1960s, the gang moved into extortion and racketeering, as well as gambling, prostitution, and drugs. The triad became closely associated with the ruling Kuomintang and the Chiang family, and Bamboo Union members were even admitted into the military, police, and intelligence academies and rose to the very top of government.
The Bamboo Union had between 70 and 80 internal organizations, having expanded from its original eight branches (Tian, De, Zhi, Zun, Wan, Gu, Chang, and Qing) to include the Zhong, Xiao, Ren, Ai, Xin, Yi, He, and Ping, and then Dong Xi Nanbei, Mei Lan Zhu Ju, and Long Shi Hu. Like the Japanese yakuza, the Bamboo Union used yubitsume (the severing of the little finger) as punishment, and it also broke the arms or legs of young members as punishment. The Bamboo Union worshipped Guan Yu as their guardian deity. By 2018, the Bamboo Union and the other main triads on Taiwan were in close cooperation due to a sluggish economy and the increasing strictness of the Taiwanese government, keeping disputes to a minimum.