Siege of Busanjin


Sō Yoshitoshi

Siege of Busanjin

Jeong Bal

Date: 4/13 of Bunroku 1 (1592)

Location:  The main fortress in Busan, Korea

Synopsis:  In the opening chapter of two invasions of the Korean Peninsula under the Toyotomi administration, Sō Yoshitoshi led forces in an assault on Fort Busan, overwhelming the defenders in a violent conflict that resulted in the occupation of Busan by the Japanese army.

Lord:  Toyotomi Hideoyshi

Commanders:  Sō Yoshitoshi, Konishi Yukinaga, Matsura Shigenobiu, Arima Harunobu, Ōmura Yoshiaki, Gotō Mototsugu

Forces:  16,700

Losses:  140

Commanders:  Jeong Bal, Yi Jeong-hyeon, Pak Hong

Forces:  600 soldiers; 8,000 civilians

Losses:  3,000 to 8,000 defenders (nearly all according to Korean records); 1,200 to 8,500 killed; 200 captured (according to Japanese records)

The Siege of Busanjin occurred on 4/13 of Bunroku 1 (1592) and was waged between the Japanese and Korean armies in Busan on the Korean Peninsula.  Along with the Battle of Dadaejin waged at almost the same time, this was one of the opening battles in two Japanese invasions of Korea under the Toyotomi administration known as the Bunroku-Keichō Campaign, named after the two eras in which each of the invasions occurred, namely, in 1592 of the Bunroku era and again in 1597 of the Keichō era.  This is also referred to as the Imjin War.

Course of events

To secure a bridgehead in Korea as well to control the sea lanes along the coast of Busan, the planners gathered in Tsushima to craft a strategy based on the knowledge of Sō Yoshitoshi, the daimyō of Tsushima, who had a detailed understanding of the situation in Korea after earlier service in a mission to Korea.  The plans involved dividing the forces to launch simultaneous attacks against the main castle in Busan along with Dadaejin and a fortress at the harbor.

In addition to Yoshitoshi, other commanders of the invasion forces included Konishi Yukinaga, Matsura Shigenobu, Arima Harunobu, Ōmura Yoshiaki, and Gotō Mototsugu, several of whom were Christian converts.

On 4/12, after sailing to Korea and prior to attacking, a vessel bearing Sō Yoshitoshi detached from the Japanese fleet with a letter to the commander of Busan, Jeong Bal, demanding that the Korean forces stand down to allow the Japanese armies provisional passage to China. Jeong Bal remained silent so, at 6:00 AM on 4/13, Sō Yoshitoshi initiated attacks against the defensive walls of Fort Busan.  In parallel, Konishi Yukinaga commenced an offensive against the fortress in Dadaejin.

Jeong Bal scuttled Korean naval vessels to prevent their capture by the invading forces and, together with local soldiers, holed-up in the fortress.

Under the protective fire of arquebuses, the Japanese soldiers used ladders to ascend the defensive walls and, owing to their extensive combat experience, the Japanese soldiers overwhelmed the defenses on the Korean side.  After incurring an attack by Sō Yoshitoshi, the Korean army withdrew to the second line of defense.  Jeong Bal regrouped his archers to launch a counterattack, but, by this time, the Korean forces had pulled back to the third line of defense.  After several hours of fighting, the Korean army depleted their supply of arrows.  Meanwhile, the Japanese army incurred its own losses so, after regrouping, commenced another round of attacks.  After being struck by arquebus fire, Jeong Bal died.  As the spirit of the Korean soldiers began to wane, around 8:00 AM on the morning of 4/13, the Japanese forces entered the castle grounds.  Many commanders of the Korean army, including the vice-envoy, Yi Jeong-hyeon, were killed.

There was nearly a clean sweep of the soldiers as well as non-combatants on the Korean side.  According to the diary of Yoshino Jingozaemon, a participant in the battle and retainer of a daimyō named Matsura Shigenobu, after the attack, the forces searched for soldiers hiding under sliding doors and stomped to death prostrating soldiers, annihilating everyone, leaving an image of bushi as terrifying demons.

Bak Hong, the Gyeongsang Left Navy Commander based on the other side of a mountain from Busan, watched from a mountaintop with surprise at the attacks on Fort Busan and, without proceeding to support the defenders, abandoned his base and naval vessels and fled.

Won Gyun, the Gyeongsang Right Navy Commander, rushed from the base for the Right Division at Geoje Island but concluded that, in the midst of the chaos, it would be impossible to gather troops and fight so he sank 100 naval vessels and cannons at sea that were owned by both navy fleets based in Gyeongsang Province in southeast Korea.  He and his close associates then fled in a small number of vessels to Kunyang.

In this manner, the Japanese army occupied Busan.  Busan was the home to many Japanese residents who originally came to engage in trade.  From this time until the end of the war, Busan served as a vital transport and logistics hub for the Japanese army, with personnel and food provisions transported on an ongoing basis from Tsushima in Kyūshū.  It served as the primary landing ground for deployments by the large army led by Kato Kiyomasa and the slightly smaller army led by Kuroda Nagamasa.


With the fall of Busan, the First Division of the Japanese army attained its initial objective.  However, to protect the bridgehead, the forces had to attack Dongnae approximately ten kilometers to the northeast of Busan.  Early in the morning on 4/14, Sō Yoshitoshi led an army that had incurred casualties to attack the fortress at Dongnae.  This lightening attack marked the next step in the opening chapter of the Bunroku-Keichō Campaign.

Alternative theories

Korean accounts tell a completely different story.  In one account, Jeong Bal, the Joseon dynasty navy captain, observed a Japanese vessel from an island, but did not think it was an enemy.  Believing that an envoy from Japan was coming, he did not prepare defenses.  On the next day, before he returned to his fortress, the siege had already begun, and although he rushed to respond, he was killed in battle.

While Jeong Bal was later conferred posthumous honors, less favorable elements of the story may have been altered.  According to the diary of a participant in the First Division commanded by Sō Yoshitoshi and Konishi Yukinaga, the conflict lasted only two hours, while another account notes that Jeong Bal died without launching a single arrow, questioning whether he engaged in a valiant fight.