Seon of Balhae

Seon of Balhae
Hangul	선왕
Hanja	宣王
Revised Romanization	Seon wang
McCune–Reischauer	Sŏn wang
Birth name
Hangul	대인수
Hanja	大仁秀
Revised Romanization	Dae In-su
McCune–Reischauer	Tae In-su

Monarchs of Korea Balhae
Go 698–719 Mu 719–737 Mun 737–793 Dae Won-ui 793 Seong 793–794 Gang 794–809 Jeong 809–812 Hui 812–817 Gan 817–818 Seon 818–830 Dae Ijin 830–857 Dae Geonhwang 857–871 Dae Hyeonseok 871–894 Dae Wihae 894–906 Dae Inseon 906–926

Dae Insu, also known as King Seon (r. 818-830) was the 10th king of the Korean kingdom of Balhae. He restored national strength, and is remembered today as the last of the great Balhae rulers before its fall.

Dae Insu was a 4th-generation descendant of Dae Joyeong's younger brother, Dae Ya-bal. In spite being from the collateral branch, he succeeded to the throne during the years of 817 and 818. He reestablished royal authority, and strengthened the military tremendously.

King Seon concentrated heavily on the empire's territorial expansion, and led campaigns that resulted in the absorption of many northern Malgal tribes including Heishui Mohe. Southwest Little Goguryeo in Liaodong was absorbed into Balhae, and also he ordered southward expansion towards Silla.

During his 12-year reign, he dispatched embassies five times to Japan, which was aimed at establishing diplomatic relations as well as increasing trade between the two kingdoms. Balhae emissaries were treated favorably even though Japan wanted Balhae to restrict the size of the embassies due to the costs associated with hosting them. The trade routes established across the Sea of Japan (East Sea) led to Balhae becoming one of Japan's most important trading partners.

He died in 830 and his grandson Dae Ijin succeeded to the throne.

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