According to the Pyeonnyeon tongnok (편년통록; 編年通錄), quoted in the Goryeosa, Wang Kŏn's grandfather Chakchegon was the son of Emperor Suzong of Tang.

[4] According to the Seongwollok (성원록; 聖源錄), quoted in the Goryeosa, the "dragon woman" was a daughter of Tu Ŭn-chŏm from Pyongju (modern-day Pyongsan County).

[6] Modern historians believe that Wang Kŏn's ancestors were influential Goguryeoic hojoks (lords) that conducted maritime trade with China for generations.

[7] According to the Gaoli tujing (c. early 12th century) written by the Song dynasty envoy Xu Jing, Wang Kŏn's ancestors were Goguryeo nobility.

[8] According to Jang Deokho, his ancestors were Goguryeo refugees who settled around Songak, accumulating great wealth through maritime trade and gaining control of the region, including the Ryesong River.

In the later years of Silla, many local leaders and bandits rebelled against the rule of Queen Jinseong, who did not have strong and wise enough leadership or policies to improve the poor condition of the people.

Wang Kŏn's ability as a military commander was soon recognized by Kung Ye, who promoted him to general and even regarded him as his brother.

In 900, he led a successful campaign against local clans and the army of Later Baekje in the Chungju area, gaining more fame and recognition from the king.

In 903, he led a famous naval campaign against the southwestern coastline of Later Baekje at Keumsung, later Naju, while Kyon Hwon was at war against Silla.

In the night of July 24, 918, four top-ranked generals of Taebong—Hong Yu (홍유; 洪儒), Pae Hyŏn-gyŏng (배현경; 裵玄慶), Sin Sung-gyŏm and Pok Chigyŏm (복지겸; 卜智謙)—met secretly and agreed to overthrow Kung Ye's rule and crown Wang Kŏn as their new king.

He promoted Buddhism as Goryeo's national religion, and laid claim to the northern parts of the Korean Peninsula and Manchuria, which he considered his rightful legacy as the successor of Goguryeo.

[15] According to the Goryeosa, in 918, the ancient capital of Pyongyang had been in ruins for a long time and foreign barbarians were using the surrounding lands as hunting grounds and occasionally raiding the borders of Goryeo; therefore, in his first year as king, Wang Kŏn ordered his subjects to repopulate the ancient capital,[16] and soon sent his cousin Wang Sing-nyŏm to defend it.

In the same year, Kyon Hwon's oldest son, Kyŏn Sin-gŏm, led a coup with his brothers Yang-gŏm and Yong-gŏm, against their father, who favored their half-brother, Kŭm-gang, as his successor to the throne.

Kyon Hwon was sent into exile and imprisoned in the temple of Geumsansa, but escaped to Goryeo and was treated like Taejo's father, who died just before his surrender.

However, Wang Kŏn's unification in 936 was a more complete unification (in which only a single state emerged among the people, as opposed to the 7th century, when two, Unified Silla and Balhae, emerged); the people of the Korean Peninsula thereafter remained under a single, unified state until 1948, when Korea was divided into north and south by Soviets and U.S. forces.