 On an other hand , Duyệt was the mandarin who charged former Crown Prince Cảnh 's wife for having an incestuous relationship with her eldest son and then executed her by drowning in 1824 . Duyệt 's action effectively ended the claim to Vietnam 's throne by Prince Cảnh 's descendants . According to one report however , Minh Mạng had already been informed from another quarter of the affair . Choi Byung Wook , a Korean historian , described this event as a " most dramatic event illustrating Lê Văn Duyệt 's loyalty to Minh Mạng " . 
