Battle of Imjin River ( 1592 ) The Battle of Imjin River ( Japanese : 臨津江の戦い ) was a battle during the Japanese invasions of Korea ( 1592 - 1598 ) . It resulted in a Japanese victory . Retreat of the King . In the Fall of 1592 , King Seonjo left Hanseong shortly before the arrival of Japanese vanguard led by Katō Kiyomasa , which forded the Han River in what is today Yongsan . At this time , the Korean public already abandoned the king and the minister , and cooperation with the Japanese army was becoming more common . Moreover , when the reinforcing Ming army retreated , the people that suffered were the civilians . Gyeongbokgung had already become ashes before the Japanese army marched through the gates , and Korean slaves greeted them as a liberation army , and set fire to the building that kept the slaves ' ledger . Following the sack of the city , Katō built an imposing Japanese castle on the Namsan mountain overlooking Seoul on what is today the site of the City Library . Seonjo and his court retreated north to Pyongyang and eventually China on foot while harassed by peasants who felt abandoned . Reaching the Imjin , and hearing of Japanese pursuit , they forded the river at night . As it was dark , they decided to burn the pavilion near the Imjin ford . The burning pavilion provided enough light to allow the King ' s party to ford the river and reach Gaeseong by morning . Little did he know that the burning pavilion was the retirement home of Yi I the late prominent scholar who had strongly petitioned to strengthen national security by enlarging the armed forces to 100 , 000 men , only ten years before . Yi I was dead by this time , but his retirement home provided for the King ' s safe retreat across the Imjin . Arrival of the Northern Border Cavalry . As the King reached Kaesong and continued north towards Pyeongyang , the northern cavalry from Hamgyeong province finally arrived . Being battle - hardened veterans of numerous border clashes against the Jurchens of Manchuria , the cavalry forces quickly moved to the Imjin River , where the forces of Katō Kiyomasa in pursuit of the king had camped on the southern bank , awaiting to ford the river . There the forces faced each other in a stalemate . According to the primary Korean record , the Korean generals debated amongst themselves over the course of action they should take . Several generals argued , " We are numerous but much of our number is weak and inexperienced ; we are relying heavily on the Northern Cavalries but they have just arrived after a long march and is tired , we should rest for a few more days to regather our strength before proceeding forward . " But they were overruled and the lead general decided to engage the enemy . Katō ' s attack . Knowing the Korean dependence on the Cavalry charge as opposed to infantry melee from Chungju , and realizing that the northern cavalry forces had yet to be exposed to Japanese arquebus fire , Katō decided to break the deadlock by drawing the Koreans into a trap . Sending a small force of light infantry " ashigaru " across the river , Katō caused the Koreans to gain unrealistic confidence , as they mowed down the ashigaru spearmen with ease in a single cavalry charge . Noticing that the charge was uncoordinated and sensing a disunity of command , Katō ordered a feigned general retreat towards the direction of Munsan from the southern banks of the Imjin . Katō ' s victory . Seeing the Japanese in an apparent general retreat , one of the two co - commanders of the Cavalry decided to ford the river in pursuit . In the dry season the Imjin River is very shallow at various points which enabled the cavalry to cross without the use of barges . As the retreat drew them in , the Korean cavalry lost all semblance of order . The pursuit became disorganized , going uphill towards Munsan . The battle turned into another episode of the Battle of Chungju . Once the bulk of Korean cavalry had entered the small valley leading from the Imjin ford to Munsan , Katō ' s arquebusiers opened fire . This had a devastating effect on the morale of the Korean cavalry . As with nearly all Korean forces , Korean cavalry had no experience with gunfire . The horses of the cavalry began to panic , bucking many of the riders . As the Koreans lay in confusion , the samurai infantry attacked from their hidden positions within the valley and began routing the Koreans . The Korean cavalry suffered many casualties in this melee while others attempting to escape drowned while trying to cross back north using deeper parts of the river . Amongst the Korean Generals Yu Geuk - ryang and Sin Hal were killed . The remaining co - commander of the Korean cavalry who had not crossed the river in pursuit , turned and escaped back to Hamgyeong province , and most or the remaining soldiers following suit . Katō Kiyomasa and his troops forded the Imjin unopposed , loaded with trophy armor and fine Korean horses . Conclusion . The defeat of the Korean cavalry at the Imjin lay open the road to Pyeongyang . There were no effective Korean maneuver units or defended castles between the Imjin and the Chinese border . Hearing of the collapse of the Imjin line , King Seonjo abandoned Gaeseong and Pyeongyang and moved further north to Uiju , where he finally met up with the first Ming contingent from China . With Ming troops joining the vestiges of his Army , Pyongyang was retaken the next year , with Japanese retreating across the Imjin back to Seoul . Korea north of the Imjin river would never be occupied again by the Japanese until the First Sino - Japanese War ( 1894 - 1895 ) . The Imjin River today . The fording site today has a small castle wall - like structure on the riverbank to show the old ferry site . The northern bank is off limits to civilians . There is an " Old Ferry Restaurant " at the fording site . Yi ' s retirement home is now restored , and is further up slope from the restaurant to the East , adjacent to the highway . The northern bank is shallow and sandy , with a large beach . The southern bank is mostly cliffs . In popular culture . This battle is celebrated in Activision ' s " Shogun : Total War " under " Imjin " . The historical error in the game is that the Koreans have infantry forces only , while Japanese have balanced combined armed forces . Also the game shows the river having a bridge , which was not the case until the 20th century .