Recent research suggests that the "burying of the Confucian scholars alive" is a Confucian martyrs' legend; rather, the emperor ordered the killing (坑 "kēng") of a group of alchemists after having found that they had fooled him. In Han times, the Confucian scholars, who had served the Qin loyally, used that incident to distance themselves from the failed dynasty. Kong Anguo (孔安國 c. 165 – c. 74 BC), a descendant of Confucius, turned the alchemists (方士 "fāngshì") into Confucianists (儒 "rú") and entwined the martyrs' legend with the strange story of the rediscovery of the lost Confucian books behind a demolished wall in the house of his ancestors. The emperor's own library still had copies of the forbidden books but most of these were destroyed later when Xiang Yu burned the palaces of Xianyang in 206 BC.