Triad societies originated in 17th century China when the Hung Mun came together in an attempt to overthrow the Qing dynasty in an unsuccessful bid to restore the Ming dynasty. Members were expected to \u00adregard each other as blood brothers, which is perhaps why they have become known colloquially as the Chinese mafia. There was a clear hierarchical structure within the group, initiation ceremonies and certain codes of conduct. In 19th century Hong Kong, members were frequently imprisoned under British law. By the 20th century, the Hung Mun had begun to break up into smaller gangs, based all over China. In 1949, the Chinese Communist Party came to power, prompting many gangs to flee to Hong Kong, as well as \u00adMacau,Taiwan and further overseas. Hong Kong soon became \u00adregarded as the triad capital, \u00adaccording to by T. Wing Lo and Sharon Ingrid Kwok. In the 1960s, there were some 60 triad gangs in Hong Kong, with one in six people said to belong to one, according to police. Drug trafficking has traditionally been a significant source of \u00adincome for gangs, with opium, heroin and cocaine all being traded. They also make money from fraud, extortion, money laundering, gambling and prostitution. They have often tried to extort money from local tradesmen or workers. Violence between rival gangs is common. Prospective gang members are required to take the \u201c36 oaths\u201d as part of their initiation ceremony, in which they pledge to help free a fellow member if they inadvertently get him arrested. If they fail, they will be \u201ckilled by five thunderbolts\u201d. Leading triad gangs in Hong Kong include the Sun Yee On, 14K and Wo Shing Wo. Between the 1950s and 1970s, the Kowloon Walled City, home to about 30,000 \u00adpeople, was largely controlled by the Sun Yee On and 14K. It fell into their hands soon after the end of the Japanese occupation in 1945, when refugees from the mainland found protection within its walls following China\u2019s civil war. The British began to adopt a \u201chands-off\u201d policy in relation to the walled city. It became a hotbed for crime. Residents also had to endure poor sanitation. The British and Chinese \u00adgovernments announced in January 1987 that the area would be \u00addemolished. Work began in 1993 and was completed the following year. The area has since been transformed into Kowloon Walled City Park. The Hong Kong police have a dedicated division that aims to combat triad activities \u2013 the \u00adOrganised Crime and Triad \u00adBureau. It is estimated there could be as many as 100,000 triad \u00admembers currently operating in the city. When the Cross-Harbour Tunnel, which opened in 1972, was being built, fights reportedly broke out between rival gangs over who would control the bus drivers travelling through it. Despite various crackdowns, triad culture continues to be \u00adimmortalised through films, \u00adartwork and video games.<\/p>\n