Establishment of Cheonghaejin

Overview

Cheonghaejin was a naval base and trading hub that Jang Bogo (Gungbok) established in the fourth lunar month of 828 (the 3rd year of King Heungdeok) at what is now Wando, South Jeolla Province, in the late Silla period. Its main garrison was on Jangdo (Janggunseom), a small island off Jangjwa-ri in Wando-eup, which was designated a historic site in 1984. Using this base, Jang Bogo suppressed pirates and led East Asian maritime trade connecting Silla, Tang, and Japan, and he also exerted influence over Silla's central politics. After Jang Bogo was assassinated, Cheonghaejin was abolished in 851 (the 13th year of King Munseong).

Background

Jang Bogo's Life in Tang

Jang Bogo's personal name was Gungbok or Gungpa, which is interpreted as meaning "one who shoots well with a bow," and he is thought to have come from common origins. In his youth he crossed to Tang together with his friend Jeong Nyeon and became a military subcommander (軍中小將) in the Wuling Army in Xuzhou. At that time, Tang was marked by regional military governors who held power locally, and along the eastern coast from Dengzhou on the Shandong Peninsula to the mouth of the Yangtze River, many Silla people lived and worked in coastal shipping and international trade.

Piracy and the Slave Trade

In the early 9th century, central control weakened in both Silla and Tang, and pirates swarmed the seas. Pirates seized residents from Silla's coasts and sold them as slaves in China, and they also threatened trading ships. In 816 (the 8th year of King Heondeok), during a famine, more than 170 starving Silla people crossed over to Zhejiang in China in search of food. Jang Bogo returned to Silla in 828 and told King Heungdeok of the misery of Silla people being captured and enslaved, and he requested permission to set up a garrison at Wando to stop the pirates.

Establishment and Structure

The Samguk Sagi records that King Heungdeok gave Jang Bogo 10,000 troops and had him establish a garrison at Cheonghae. The Encyclopedia of Korean Culture explains that, since the central government lacked the capacity to extend its power directly, Jang Bogo gathered local people under the king's approval and secured more than 10,000 men in what was effectively a civil-military organization. The title Cheonghaejin Daesa (Commissioner of Cheonghaejin) given to him did not exist in the Silla official system, so Cheonghaejin was from the outset an independent power centered on Jang Bogo himself.

Wando lay at a crossroads of sea routes that ran from the mouth of the Yangtze River or the Shandong Peninsula across the Yellow Sea, past Heuksando, to the southern coast of the Korean Peninsula and to Kyushu in Japan. The main garrison on Jangdo had deep water suitable for mooring ships and offered shelter from typhoons, making it a strategic site. Wooden palisades were densely driven around the island to block the approach of outside vessels, and the island was divided into inner and outer fortifications with multiple layers of walls. A watchtower in the middle of the island allowed observation of the southern coast and the waters off Haenam and Gangjin.