 After the coup he arrested his own brother, Anpyeong, first sending him into exile, then sentencing him to death.Finally in 1455 he forced his powerless young nephew, Danjong, to abdicate, declaring himself seventh king of the Joseon dynasty.Later he demoted Danjong to prince and ordered him to be poisoned after his younger brother, Grand Prince Geumsung, and later six scholars including Seong Sam-mun, Pak Paeng-nyeon, and Yi Gae plotted to remove Suyang from power in an attempt to put Danjong back on the throne.