Empress Lü Zhi
Wu Zetian eliminated many of her real, potential, or perceived rivals to power by means of death (including execution, suicide by command, and more-or-less directly killing people), demotion, and exile. Mostly this was carried out by her secret police, led by individuals like Wao Ganjun and Lai Junchen—who were known to have written a document called the "Manual of Accusation", which detailed steps for interrogation and obtaining confessions by torture. One of these methods, the "Dying Swine's Melancholy" (), which merely indicated a level of pain inflicted by a torture device, seems to have been conflated in the years following Wu's death with the story of the "human swine" torture conducted by Empress Lü Zhi, in which the victim had limbs and tongue amputated, was force-fed, and left to wallow in his own excrement.