The Didouyu () or Didougan () was a tribe during the 5th-century in western Manchuria. Their territory included the Tujue (Eastern Turk, on their west), the Rouran, and the Khitan (on their southeast). They were attacked by both Goguryeo and Rouran in 479, allied for this operation.太和三年, <高句麗> 竊與< >謀, 欲取<地豆于>以分之, Book of Wei. In fear, a big part of Kithan fled southward to submit to Northern Wei.Xu Elina-Qian, p.264 + 296a Didouyu were one of the northern branches of the Xianbei.
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