Jo Gwang-jo
However, the Sarim faction, whose origin stems from denial of the legitimacy of Joseon dynasty, was vulnerable to Hungu's attacks because it questioned the legitimacy of King Sejo's usurpation and primarily engaged in the censorate role against the king and ministers. After four major purges that saw Jo Gwang-jo and many others executed, the Sarim scholars again retreated to rural villages where they continued to spread their philosophy through local schools called seowon and maintained their power base through the system of Hyang'yak.