Despite its briefness, “Kogi” (Ancient Records), which is cited in “Northern Buyeo Articles” in Samguk yusa , includes important content that provides an important clue for understanding history Northern Buyeo and the lineage and establishment of the foundation myths of Buyeo and Buyeo-descent nations such as Koguryo. In fact, these records were originally separate ones dealing with the foundation myth of Northern Buyeo with no connection to that of Koguryo. Although they do not remain intact, it is thought that the records originally contained the genealogical relationship between Haemosu (Father), the daughter of Habaek (Mother), and Haeburu (son). Other records, except for the “Northern Buyeo Articles” in Samguk yusa , do not state that there is a blood relationship between Haemosu and Haeburu. This is because the Haemosu-Haeburu myth went through a transformation in the process of being incorporated into the foundation myth of Koguryo.
What matters here is the relationship between the foundation myth of Northern Buyeo and the myth of King Dongmyeong of Buyeo. The foundation myth of Northern Buyeo is very similar to the myth of Dangun in terms of structure, while it has no correlation with the myth of King Dongmyeong, a type of transmitted heroic tale, in terms of lineage. Thus, in order to reasonably understand the relationship between the two myths, Buyeo and Northern Buyeo should be regarded as two separate states. The existing view that equates Buyeo with Northern Buyeo has not been able to properly explain the relationship between the two myths. In addition, the Eastern Buyeo capital-transfer myth, which represents Haeburu moving to Geumwa, can also be considered as an independent foundation myth of Eastern Buyeo in terms of lineage because it is a type of emergence myth, which is different in terms of its establishment.
Accordingly, the foundation myth of Northern Buyeo, that of Eastern Buyeo, and the myth of King Dongmyeong should be strictly distinguished from one another. Furthermore, based on this, the establishment of the foundation myth of Koguryo, the significance of Haeburu to the Buyeo tribe, and the ethos of succession of Koguryo and Baekje to Buyeo need to be reconsidered. In this regard, the establishment of the foundation myth of Koguryo is as follows. The myth in the early years of Koguryo shared certain literary similarities with the foundation myth of Northern Buyeo, and yet employed the structure of the myth of King Dongmyeong in terms of expression. Therefore, it did not include Haemosu and Haeburu, who appear in the Northern Buyeo myth, but presented the daughter of Habaek as the mother of Jumong. According to the ritual system of Koguryo in the sixth century as recorded in the “Gaoguli zhuan” in Zhoushu , it is clear that this structure of the myth remained the same until the sixth century. The current foundation myth of Koguryo that encompasses Haemosu and Haeburu was formed during the compilation of Shinjip in the late years of Koguryo. This was part of the ideological integration policy for settling the political chaos since the late sixth century by combining the myths of the Buyeo descent nations that belonged to Koguryo.