Emperor Taiwu of Northern Wei
"Róurán" 柔然 is a Classical Chinese transcription of the endonym of the confederacy; 蠕蠕 "Ruǎnruǎn" ~ "Rúrú" (Weishu), however, was used in Tuoba-Xianbei sources such as orders given by Emperor Taiwu of Northern Wei. It meant something akin to "wriggling worm" and was used in a derogatory sense. Other transcriptions are 蝚蠕 "Róurú" ~ "Róuruǎn" (Jinshu); 茹茹 "Rúrú" (Beiqishu, Zhoushu, Suishu); 芮芮 "Ruìruì" (Nanqishu, Liangshu, Songshu), 大檀 "Dàtán" and 檀檀 "Tántán" (Songshu).