Fought only months after the Japanese invasion of Korea began, this engagement marked the first major Korean land victory over a large Japanese army and helped prevent the invasion from spreading into the fertile southwestern provinces. Along with the naval victory at Hansan Island and the later Battle of Haengju, it is traditionally regarded as one of the three decisive Korean victories of the war. 

By the autumn of 1592, Japanese forces under Toyotomi Hideyoshi had achieved a stunning series of victories. Busan, Seoul, and Pyongyang had all fallen in rapid succession, and much of the Korean military had been scattered or destroyed. However, Japan's strategic situation had begun to deteriorate. Admiral Yi Sun-sin's repeated naval victories had severely disrupted Japanese supply lines, making it increasingly difficult to support armies deep inside Korea. At the same time, Korean "Righteous Armies" (volunteer militias formed by civilians, scholars, monks, and local officials) were launching attacks against isolated Japanese units. Faced with growing logistical problems, the Japanese sought to secure the southwestern province of Jeolla, Korea's richest agricultural region, which could provide food and resources for the invasion. Standing in their way was the fortress city of Jinju. 

Jinju was defended by the magistrate and military commander Kim Si-min, who commanded approximately 3,800 regular soldiers, supported by more than 2,000 local militia and civilians. Although vastly outnumbered by an attacking Japanese force of roughly 30,000 men led by Ukita Hideie and other experienced commanders, Kim carefully prepared the city's defenses. The garrison possessed around 170 arquebuses, comparable in quality to Japanese firearms, and stockpiled arrows, stones, and explosive weapons. Men and women alike participated in the defense, carrying supplies, hurling rocks, and helping maintain the walls throughout the battle. 

The Japanese assault began with intense arquebus fire followed by repeated attempts to storm the walls using ladders. These methods had proven highly successful against many Korean fortresses earlier in the campaign. At Jinju, however, they encountered determined resistance. Kim Si-min coordinated disciplined volleys of gunfire while defenders rained arrows, stones, and explosive devices onto attackers attempting to scale the walls. Every assault was repulsed, and the Japanese suffered unexpectedly heavy casualties. The defenders also used psychological deception, such as placing scarecrows and having civilians appear as soldiers, making the garrison seem larger than it actually was. 

The fighting was fierce and continuous over several days. During the siege, Kim Si-min was struck in the head by an arquebus bullet and was mortally wounded. Despite the loss of their commander and dwindling ammunition supplies, the defenders refused to surrender. Leadership passed to subordinate officers, who maintained discipline and continued resisting repeated Japanese attacks. 

Meanwhile, the famous Righteous Army leader Gwak Jae-u approached Jinju with only a small force. Realizing he lacked the strength to break the siege directly, he ordered his men to blow horns, beat drums, and create as much noise as possible throughout the surrounding countryside. Additional irregular fighters joined, convincing the Japanese commanders that a substantial Korean relief army was arriving. Already exhausted by heavy losses and fearing encirclement, the Japanese abandoned the siege and withdrew. 

Although Korean casualties were significant (including the eventual death of Kim Si-min from his wounds) the Japanese losses were far greater, with contemporary estimates placing their dead at over 10,000 men. More important than the numbers was the psychological impact of the victory. Until Jinju, Japanese armies had seemed nearly unstoppable on land. The successful defense demonstrated that disciplined leadership, strong fortifications, effective use of firearms, and cooperation between soldiers and civilians could defeat even a numerically superior Japanese force. The victory greatly boosted Korean morale during one of the darkest periods of the war. 

Strategically, the First Siege of Jinju prevented the Japanese from immediately advancing into Jeolla Province, preserving Korea's principal agricultural region from conquest and denying the invaders a vital source of food and supplies. It also bought valuable time for Korean resistance to strengthen and for Ming China to prepare its intervention. However, the triumph came at a heavy cost. Determined to erase the humiliation of their defeat, the Japanese returned in the summer of 1593 with an overwhelming force of around 90,000 troops. The Second Siege of Jinju** **ended in a Japanese victory and the destruction of the fortress, followed by the massacre of most of its defenders and many civilians inside the city. 

Painting by Kim In-hwa

Depiction of Korean General Kim Si-min during the First Siege of Jinju, 1592, Imjin War