1. Overview
Gukjo Won덕daewang (국조 원덕대왕Gukjo Won덕daewangKorean, literally "National Ancestor, King Won덕") was a posthumous title given to one of the key ancestral figures of King Taejo Wang Geon, the founder of the Goryeo dynasty. While King Taejo, two years into his reign, posthumously honored his paternal great-grandfather Wang Ryung as Sejo and his paternal great-great-grandfather Wang Jegŏn as Uijo, the precise identity of the figure designated as Gukjo remained a subject of historical debate. The title "Gukjo" signifies a foundational ancestor of the royal family, and the conferral of the posthumous name "Won덕daewang" was intended to solidify the legitimacy of the newly established Goryeo dynasty. This article explores the various historical accounts and scholarly interpretations regarding Gukjo's true identity, the lineage connecting him to King Taejo, and the broader implications of these historical narratives for the Goryeo royal house.
2. Identity Controversy
The historical records concerning the true identity of Gukjo are complex and present differing viewpoints, leading to significant scholarly debate throughout the Goryeo period.
2.1. The Po-yuk Theory
According to early historical records such as the *편년통록P'yŏnnyŏn t'ongnokKorean* and the *고려사절요Koryŏsa chŏryoKorean*, Gukjo is identified as Kang Po-yuk (강보육Kang Po-yukKorean). The official history of Goryeo, the *Goryeosa*, also cites *P'yŏnnyŏn t'ongnok* in stating that Kang Po-yuk, originally known as Sonhosul (손호술SonhosulKorean), later changed his name to Po-yuk. These records assert that Kang Po-yuk was the great-great-grandfather of King Taejo.
Kang Po-yuk's lineage is detailed as follows: he was the son of Gang Chung (강충Gang ChungKorean), and a 67th-generation descendant of Kang Suk (康叔Kang SukChinese), who was the second son of a Chinese noble from Jingzhao Commandery. Kang Po-yuk had two brothers named Ijegŏn (이제건IjegŏnKorean) and Po-sŭng (포승Po-sŭngKorean). He married his niece, Kang Tŏk-chu (강덕주Kang Tŏk-chuKorean), who was the daughter of his brother Ijegŏn. Their daughter was Kang Chin-ŭi (강진의Kang Chin-ŭiKorean), who would become the mother of Jakchegŏn, King Taejo's paternal great-great-grandfather and the figure later known posthumously as Uijo.
2.2. Criticisms and Alternative Theories
Despite the prominence of the Po-yuk theory in early records, later Goryeo scholars raised significant criticisms, questioning the identification of Kang Po-yuk as Gukjo. One of the most prominent critics was Yi Che-hyŏn (이제현Yi Che-hyŏnKorean), a distinguished scholar of the late Goryeo period.
Yi Che-hyŏn, as cited in the *Goryeosa*, argued that it was illogical for Po-yuk to be given the temple name Gukjo, especially considering he was not a direct male ancestor of the House of Wang (the royal clan of Goryeo). Traditionally, Po-yuk was portrayed as the maternal grandfather of Jakchegŏn (Uijo), meaning he was an external maternal ancestor rather than a direct patrilineal one. Yi Che-hyŏn questioned why Po-yuk would be honored with a temple name over his son-in-law, who was King Taejo's paternal great-grandfather.
Yi Che-hyŏn pointed to the *Wangdae Chongjok-ki* (왕대종족기Genealogical Record of the Wang DynastyKorean), a now-lost work, which stated that King Taejo's great-grandmother, Jeonghwa Wanghu, was the queen of Wang Gukjo. This implies that Gukjo should have been King Taejo's great-grandfather, the husband of Kang Chin-ŭi. The *Sŏngwŏnrok* (성원록SŏngwŏnrokKorean) further stated that "Po-yuk sŏngin" (Saint Po-yuk) was the maternal grandfather of Won덕daewang, the figure identified as Gukjo. If Jeonghwa Wanghu (Kang Chin-ŭi) was indeed the daughter of Kang Po-yuk, then Gukjo, as her husband, could not also be Kang Po-yuk himself. This created a clear logical inconsistency for Yi Che-hyŏn.
The identity of Kang Chin-ŭi's husband was also a point of contention. While traditional accounts, particularly in *P'yŏnnyŏn t'ongnok* and *Koryŏsa chŏryo*, suggested her husband was a Tang imperial family member, possibly Emperor Suzong, other texts like *P'yŏnnyŏn gangmok* (편년강목P'yŏnnyŏn gangmokKorean) proposed Emperor Xuanzong. This foreign connection was already disputed by the late Goryeo period, further complicating the narrative of the royal lineage.
During the late Goryeo period, another scholar, Yi Saek (이색Yi SaekKorean), put forward an alternative claim, suggesting that Gukjo was, in fact, Gang Ho-gyeong (강호경Gang Ho-gyeongKorean), an earlier ancestor of the Kang clan, rather than Kang Po-yuk. These persistent debates underscore the efforts to construct and legitimize the royal ancestry of the Goryeo dynasty.
3. Relationship with King Taejo and Lineage
The ancestral connection between Gukjo and King Taejo Wang Geon is central to understanding the Goryeo royal lineage, particularly given the various theories regarding Gukjo's identity. Regardless of the specific individual identified as Gukjo, he represents a pivotal figure in the foundational myths of the Kaesong Wang clan (개성 왕씨Kaesong Wang-ssiKorean), King Taejo's ancestral line. The Kaesong Wang clan regards Gukjo as its progenitor.
The lineage, as pieced together from various historical accounts, typically traces back through several generations to King Taejo. Kang Ho-gyeong is mentioned as an early ancestor of the Kang clan, whose son was Gang Chung. Gang Chung, in turn, had two notable sons, Ijegŏn and Kang Po-yuk.
The lineage then proceeds as follows:
- Kang Po-yuk married his niece, Kang Tŏk-chu (daughter of Ijegŏn).
- Kang Po-yuk and Kang Tŏk-chu had a daughter named Kang Chin-ŭi, who would later be posthumously honored as Jeonghwa Wanghu.
- Kang Chin-ŭi had a son, Jakchegŏn (작제건JakchegŏnKorean), with a man identified as a member of the Tang imperial family. Historical sources dispute whether this Tang emperor was Emperor Suzong of Tang or Emperor Xuanzong of Tang. Jakchegŏn is also known by his posthumous title, Uijo Gyeonggangdaewang (의조 경강대왕Uijo GyeonggangdaewangKorean).
- Jakchegŏn, while on a journey to find his father in Tang China by crossing the Yellow Sea, encountered a Dragon Lady, the daughter of the Yellow Sea Dragon King. This Dragon Lady is also identified as the daughter of Tou-en-dian Ganjue (頭恩坫角干Tou-en-dian GanjueChinese) from Pingzhou (平州PingzhouChinese), China, and was later posthumously named Wonchang Wanghu (원창왕후Wonchang WanghuKorean).
- Jakchegŏn and Wonchang Wanghu had a son named Wang Ryung (왕륭Wang RyungKorean). Wang Ryung was later posthumously honored as Sejo Wimu Daewang (세조 위무대왕Sejo Wimu DaewangKorean).
- Wang Ryung was the father of Wang Geon, the founder of the Goryeo dynasty.
In summary, the lineage from the most commonly cited Gukjo (Kang Po-yuk) to King Taejo proceeds from Kang Po-yuk to his daughter Kang Chin-ŭi, then to her son Jakchegŏn (Uijo), then to Jakchegŏn's son Wang Ryung (Sejo), and finally to Wang Ryung's son, King Taejo Wang Geon. The Korean historical records further confirm that Gukjo was considered King Taejo's great-grandfather (although sources debate if this refers to the paternal great-grandfather or a more general ancestral figure), the father of Uijo, and the grandfather of Sejo, thereby establishing the crucial ancestral chain that underpinned the Goryeo royal family's claims to power.
| Relationship | Title | Relationship | Title |
|---|---|---|---|
| Son | Uijo Gyeonggangdaewang 懿祖 景康大王 | Queen 王后 | Wonchang Wanghu Du clan 元昌王后 頭氏 |
| Grandson | Sejo Wimu Daewang 世祖 威武大王 | Queen 王后 | Wisuk Wanghu Han clan 威肅王后 韓氏 |
4. Posthumous Title and Enshrinement
The conferment of the posthumous title Won덕daewang (원덕대왕Won덕daewangKorean) upon Gukjo holds significant political and symbolic importance for the nascent Goryeo dynasty. Two years after his enthronement in 918 CE, King Taejo undertook the crucial act of posthumously honoring three generations of his direct paternal ancestors, a practice essential for establishing the legitimacy and prestige of his new ruling house. During this process, his great-grandfather (or, as per some interpretations, his great-great-grandfather) was officially designated as "Won덕daewang."
The *Goryeosa* chronicles this event, stating that King Taejo "posthumously honored three generations" and elevated his "great-great-grandfather to be 'Sijo Won덕daewang' (始祖元德大王)" and his consort to be "Jeonghwa Wanghu" (貞和王后). This act was not merely an honorific gesture; it was a deliberate political statement. By formally acknowledging and elevating his ancestors with royal titles, King Taejo aimed to solidify the Goryeo dynasty's divine and historical mandate to rule. It asserted a deep-rooted lineage that extended beyond his immediate family, connecting his reign to a venerable past. This ceremonial enshrinement of Gukjo as Won덕daewang, along with Uijo and Sejo, provided a robust ancestral foundation for the new dynasty, reinforcing its stability and authority in the eyes of the populace and the aristocracy.
5. Historical Assessment
The concept and identity of Gukjo, particularly the ongoing controversy surrounding who exactly held this foundational title, offer a critical lens into the establishment and legitimization of the Goryeo royal family. Across different historical periods, scholars and chroniclers have presented various interpretations, each reflecting the prevailing political and social needs of their time.
The initial identification of Kang Po-yuk as Gukjo in texts like *P'yŏnnyŏn t'ongnok* and *Koryŏsa chŏryo* likely served to provide a concrete, albeit maternally linked, ancestor for King Taejo, emphasizing a connection to established, albeit non-royal, lineage. However, the later criticisms by prominent scholars like Yi Che-hyŏn highlight a shift in historical scrutiny and a desire for a more direct, patrilineal succession to the Goryeo throne. Yi Che-hyŏn's arguments underscore the importance of a patrilineal succession for dynastic legitimacy, as he questioned why an external maternal ancestor would be given such a paramount royal title over a direct male forebear. His reference to the *Wangdae Chongjok-ki* and its assertion that Gukjo was King Taejo's paternal great-grandfather (the husband of Kang Chin-ŭi) reflects an attempt to align the foundational ancestor more closely with a direct patrilineal line, even if it involved a disputed Chinese imperial connection.
The proposal of Gang Ho-gyeong by Yi Saek further demonstrates the fluidity and political utility of constructing ancestral narratives. Such debates surrounding Gukjo's identity indicate a dynamic interplay between historical fact, genealogical claims, and the political imperatives of the Goryeo court. The ambiguity and varied accounts suggest that the royal family's ancestry was not entirely settled or universally accepted, leading to ongoing efforts to establish a definitive and legitimizing lineage. Ultimately, the controversy over Gukjo's identity, whether Kang Po-yuk, a Tang emperor, or Gang Ho-gyeong, reflects the Goryeo dynasty's persistent efforts to solidify its foundation by constructing a noble and coherent ancestral narrative, an essential task for any ruling house seeking to affirm its mandate and authority.