Yang was a salesman of firewood in Guangxi province before he joined the rebellion. In 1848 he converted to Christianity after reporting that he had experienced visions of God. In 1850 he began to claim that he could miraculously heal true believers. He was an early participant in the rebellion and rose quickly to prominence; in 1851, when Hong Xiuquan took the title of Heavenly King for himself, Yang was made commander-in-chief of the army. Yang was further named "East King", in keeping with three other leaders of the rebellion who were given titles as "kings" the four quarters of the Heavenly Kingdom. Yang devised an extensive network of spies to root out the intrigues of loyalists in the kingdom. By the 1850s Yang became the most powerful leader of the Taiping Rebellion.
Under Yang's direction, the city of Nanjing (Nanking), which became the capital of the Heavenly Kingdom, was taken in 1853. As Hong became increasingly disinterested in politics and more interested in his harem, he named Yang as his prime minister for the Heavenly Kingdom. Yang clashed with Hong over the rebellion's policies and views toward Confucianism and iconoclasm; Yang believed that Confucian morality was essentially positive and that its basic tenets were compatible with the rebellion's interpretation of Christianity and that images of dragons were not sacrilegious. Hong, however, rejected this notion and believed that Confucianism ought to be eradicated, as it was the work of the devil. This, and Yang's conspiracies for greater power raised Hong's ire, and in 1856, Yang was murdered by Hong's followers. In the three months that followed, Hong slaughtered Yang's family and thousands of the dead East King's adherents. The fortunes of the Taiping Rebellion subsequently declined as the rebellion's leaders became involved in internecine conspiracies and intrigues.eo:Yang Xiuqing zh:杨秀清