and had sold out his father Tuoba Shiyijian to Former Qin. (See here for more details; under the later official history, however, Tuoba Shiyijian was Emperor Daowu's grandfather, not father.) He believed that Cui was in conflict with Crown Prince Huang, and that it was at Crown Prince Huang's direction that Gao attributed the histories' authorship as indicated—because the key problematic passage would come from Tuoba Shiyijian's biography, not Emperor Daowu's, and Gao was silent as to who wrote Tuoba Shiyijian's biography. Bo's analysis is itself speculation, but might be considered a reasonable explanation for what happened to Cui. Bo also believed that Cui was poisoned—which would explain why he was not able to respond at all to Emperor Taiwu's interrogation, and was later only yelling "Ao Ao" in lament, unable to say anything. References Old Book of Tang, vol. 35. History of Northern Dynasties, vol. 21. Zizhi Tongjian, vols. 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125. 4th-century births 450 deaths Northern Wei Taoists Chinese chancellors Northern Wei historians 5th-century Chinese historians Northern Wei poets Northern Wei politicians Executed Northern Wei people People executed by Northern Wei 5th-century executions Persecution of Buddhists Cui clan of Qinghe 5th-century Chinese poets