 Jo died in 1958.His disciples continued as a single religious order until 1968, recognizing as Jo's successor Park Wudang (1918-1996, or 1917-1995 according to the lunar calendar normally used by the movement).In 1968, however, Park's authority was contested by a number of senior executives and by one of Jo's sons, Jo Yongnae, who opposed the reforms Park had introduced.