The Records of the Three Kingdoms records that the Yilou were located more than a thousand li north of Buyeo in forests covering mountainous terrain that had formerly been the kingdom of the Sushen clan. The text reports that, although the Yilou were subjects of Buyeo, they did not speak the same language as the people of Buyeo and Goryeo.
The Records of the Three Kingdoms state that the Yilou were positioned more than a thousand li north of Buyeo in wooded mountainous areas that once belonged to the Sushen clan. The text suggests that, although under Buyeo's rule, the Yilou did not speak the same language as those of both Buyeo and Goryeo.