Wu Zetian was a concubine in the courts of Emperor Tai Tsung in Tang Dynasty China and later in the court of his son, Emperor Kao Tsung. Through cold, calculated, and brutal maneuvering she convinced the emperor that his wife had murdered his son. Wu replaced her as empress and maneuvered again to have her weakest son succeed Kao Tsung as emperor and effectively ruled in his stead until he removed himself leaving her in complete control as empress. Confucian teachings held that women were unfit to rule so Wu set about changing this view of women by elevating women to high government positions. She also replaced the existing system of government positions going to aristocratic families with testing for merit.