It was deemed the worldwide second tier most bloody revolt after WWII, with a estimated death toll of 20-30 million, and took place in 17 provinces of China between 1850 and 1873.
A little time after that the Qing dynasty had lost the First Opium War (1839-1842) against England, the popular dissatisfaction grew in southern China. It was a commercial war in which China sought to spoil the opium commerce that was in British hands, and as a result of this China had lost Hong-Kong, five ports and owed a war indemnification of about 21 million dollars.
In this state of popular riot for the penuries of postwar period against the Qing dinasty, grew the figure of the charismatic leader Hong Xiuquan, who was preaching a fundamentalist Christianity, declaring himself a minor brother of Jesús and dressing as the Popes of Occident.
Hong Xiuquan created a Christian theocratic state, the Taiping Heavenly Kingdom, and his fanatical followers were joining daily between the southern majority Han against the northern minority of the Manchu, from which the dynasty Qing was coming.
The principal policies of the new kingdom were a combination of the tridentine views of Benedict XVI and the economic views of Karl Marx. They combines the radical change from the Confucianism to the Christianity, the abolition of the private property, the slavery, the abolition of the differences between sexes and the change of the lunar calendar for the solar calendar. The sex was prohibited in a special way, even inside the marriage, and were punished as serious crimes the concubinage, the poligamy and the prostitution.
The rebels captured Nanjing in 1853 and made it their capital. The western powers, who at first sympathized with the movement, soon realized that the Ch'ing dynasty might collapse and with it foreign trade. They offered military help and led the Ever-Victorious Army, which protected Shanghai from the Taipings. The Taipings, weakened by strategic blunders and internal dissension, were finally defeated by new provincial armies led by Tseng Kuo-fan and Li Hung-chang.
Britons helped the Qing dinasty to fight the taipings with “soldiers of fortune”as Frederick Townsend Ward, a USA born mercenary who fought with William Walker in Mexico and Nicaragua, with Garibaldi in Italy, and with the Frenchs in the Crimean War.
Another famous “soldier of fortune”, Charles George “Chinese” Gordon helped too the Qing dinasty (and the wealthy british opium trade). He knew Townsend Ward in the crimean War, and was appointed previously by the brits in Sudan, India, Mauritius, and in Cape Colony (nowadays in South Africa). Gordon was finally died by the Mahdists at Khartoum, Egypt.