The Legends of Southward Migration And Related Issues in The"Preface"of The Book of Wei
The legends of the southward migration of various Xianbei tribes are highly similar in morphological struc-ture and content motifs,confirming the belief that Wuhuan,Rouran and other tribes all originated from Mobei,belonging to the Donghu groups.These legends all emphasize that they originally came from Mobei,affirming the key role of southward migration in shaping their tribal organization and personality characteristics.Moreo-ver,the legends not only superimpose the memory of Donghu's origins,and the prehistory,birth history and formation history of Wuhuan and Xianbei related tribes,but also reflects the sorting out of inherited traditions by these tribes from the legendary era into the historical period.Revealing this state of overlapping multiple time and space connotations is the key to reasonably discover the historical shadow of the legend of the south-ward migration and to properly interpret the content of the"Preface"of The Book of Wei.