Battle of Byeokjegwan

The Battle of Byeokjegwan (or Pyŏkje) (Chinese: 碧蹄館大戰; Bì tí guǎn dàzhàn) was a battle fought on January 27, 1593 (January 26 according to the Japanese calendar of the time), between the armies of the Ming Dynasty led by Li Rusong, and the Japanese forces under Tachibana Muneshige, Ukita Hideie, and Kobayakawa Takakage. As part of the Japanese Invasion of Korea (Imjin War), it was the first field battle fought during the war between the two sides.

Background
Li Rusong and the Ming army of 36,000 set out from Liaodong on December 25, 1592, in an effort of the Ming army to aid the Joseon Dynasty, which had already largely been overrun by Japanese forces. Li was initially successful, and he retook Pyongyang in a one-day direct assault on January 8. He recaptured the major city of Kaesong not long after.

The capital city of Seoul was the Ming force's next target. Li began to send early scouting parties towards Seoul in late January. A few skirmishes occurred between the two sides. Li left behind a few thousand men to defend Pyeongyang and Kaesong and set out for Seoul with his main force.

Battle
On the 26th of January, Li was notified by allied Korean scouts that the Japanese forces had withdrawn from Seoul and it was now an undefended city. Encouraged by this (false) report, Li left behind all of his infantry and artillery, and set out with a large number of his generals and their immediate retinues. Figures vary, but most cite between 1,000 to 3,000 men. This force, made up entirely of cavalry, set out to join their advance scouts and hoped to reach and secure Seoul immediately. The two forces combined for some 5,000 to 7,000 cavalry.

On the same morning, Li's advance party, under General Zha Dashou (查大受) along with the Korean general Go Eon-baek (고언백(高彦伯)) approached the Byeokjewan area north of Seoul. The Japanese force became aware of the advance and Tachibana Muneshige sent out a small party of 500 to 600 men to lure the Ming army forward. The Ming party took the bait and attacked the Japanese party. The Ming advance party was soon met by Muneshige's main force (3000 strong) coming in from the flanks and was forced to pull back, becoming trapped in the nearby hills.

Li Rusong, upon hearing of the plight of his advance party, moved forward and tried to relieve his besieged scouts. He managed to meet up with his scouts around noon, only to be met with an even larger relief army from the Japanese side as other daimyo's forces from the area also converged on Byeokjegwan.

Li Rusong was now trapped with his forces facing a Japanese army of between 30,000 to 40,000 men. They were again forced to try to defend themselves on a hill. The muddy field conditions and narrow nature of the area made it difficult for them to utilize their horses, so the force mostly dismounted and fought on foot.

The Japanese forces advanced on the Ming position around 10 am. The initial attack by Ukita Hideie's forces was pushed back by the Ming, and then came an all out advance with Muneshige's force coming in from the right, Ukita Hideie's force coming in from the front, and Kobayakawa Takakage's force coming in from the left. Muneshige's forces fired off a volley of teppō before charging head on into the Ming forces.

The Ming forces were without their heavy equipment or infantry support, but were made up almost entirely of their most elite retinue warriors. The two sides clashed and the Ming generals themselves were forced to fight in hand-to-hand combat for most of the battle. Li Rusong's brother, Li Rumei, shot a samurai warrior (Ono Nariyuki) at point blank range as he was about to duel with his brother. One of the Ming officers, Li Yousheng (李有聲), was killed while trying to defend Li Rusong. Several samurai of note also perished in the battle.

The all-out brawl continued from 10 am to midday, while Japanese forces sent several waves up against the Ming position and both sides took significant casualties. Around noon it started to rain, and the broken ground began to resemble a swamp, making the melee fighting difficult. Changing tactics, Kobayakawa drew back his samurai to allow a field of fire for his arquebus squads, which shot bullets into the mass of Chinese and Koreans. The Japanese then pursued the defeated Ming army back up the pass to its highest point, and after a few more hours of fighting, Kobayakawa ordered the advance to cease as darkness fell. The Japanese forces, not ready to commit to an all-out field battle with the Ming's main force, pulled back towards Seoul, and the Ming army, having taken heavy losses among their elite warriors, also pulled back towards Kaesong.

Casualties
As with many battles in the Imjin war, the casualty figure is wildly different depending on the source. Li Rusong first reported a casualty figure of 264 against a kill of 167 enemies to the chief overseer Song Yingchang, though it was later blasted by other Ming officials back home of being faulty. An investigation concluded that the actual casualty figure was closer to the 2,000 range (as many of the retinue soldiers killed were off-the-record soldiers, the on-record soldiers casualty was indeed in the 200s). The first Korean report on the battle relayed a story from a different Ming general that was not directly involved in the battle that the Ming lost 1,500 men while only killing a little more than a hundred foe, while the Japanese records seem to suggest that they lost 2,000-3,000 men while killing 6,000 men of the Ming force. One source in particular suggests that the Ming lost 20,000 men, (which would have been around 60% of the entire Ming army in Korea at that time).

Given the nature of the battle and the maneuvers of both sides in the days and months after the battle, it could be estimated both sides lost between 2,000 to 5,000 men, though the Ming casualties were almost entirely among their elite retinues, which made the number more significant than it would appear.

Other controversies
Although the official version of the story was that Li Rusong and the Ming forces were misled by faulty Korean intelligence, some of the other Ming generals (especially those that originated from the South) claimed that in fact it was Zha Dashou who misled Li and the other Ming forces. Zha thought that the Japanese forces were on the verge of collapse, and thus a fast and sudden advance on their position would cause them to pull out of Seoul, and as the vanguard of the group, he would gain the largest share of the glory. The generals cited that almost all of them were caught by surprise by Li's sudden departure the day before the battle, and scrambled to catch him.

The battle and other disputes at Pyongyang and elsewhere led to an ever increasing friction between the Ming officers of different origins.