Battle of Byeokjegwan — Part 1: a detailed reconstruction

Per Gunsen History's request, let's talk about Imjin War!

I rarely write about Imjin War topic. Truth be told I don't recall ever written anything about it in this blog, as various sources and analyses usually contradict each other, making the prospect of doing an through overview on the subject difficult. I also lack academic expertise, time, and resource to do independent research on my own.

That being said, I am well aware of the scarcity of English-language resources on this subject. To make matters worse, most English resources do not make use of many Chinese primary sources, thus painting an incomplete and often biased picture on the war.

Luckily, there has been growing interest in Imjin War from China as well, especially among the Mainland Chinese netizens. I often find their studies on Imjin War highly comprehensive and informative, as what they lacked in professional academic training they more than made up with access to vastly greater range of primary and secondary sources, mastery of all the languages used in these sources (namely Chinese and Japanese, as most ancient Korean documents were also written in Chinese), better understanding of the cultural quirks and norms of the period (being Chinese and all), deeper focus, and attention to details, as the following reconstruction of Battle of Byeokjegwan will show.

Before I start though, I should reiterate that this article is NOT written by me — I merely translated it to English (with some heavy formatting on my part) for wider audience. The original Chinese articles can be found here and here.




『吾兵雖云乘勝，實遠來疲罷。倭奴集各道之兵与王京，且有以虎視石之戒，正未可輕敵也。』
"Although our troops appear to be on high morale (following the victory at Pyongyang), in reality they are already weary from the long march. The Japanese are recalling their troops from various provinces to the Capital, so we should heed to the wisdom of  'assigning a tiger to keep watch on a stone', and not to underestimate them."

Prelude
When Ming army finally reached Imjin River, they had marched for more than one thousand li (576 km) away from their homeland at Liao Dong (遼東, present-day Liaoning). At the same time, Japanese army had gathered more than 50,000 troops in Hanseong (한성 or 漢城, present-day Seoul), nearly twice the number of Ming troops, and Katō Kiyomasa (加藤清正) still had several thousand troops stationed at Hamgyong Province on top of this, threatening Ming flanks at Hwanghae Province and Pyongan Province. If Ming army was able to quickly recapture Hanseong, then they could cut off Katō Kiyomasa from the rest of the Japanese army completely. Otherwise, they might had to consider retreating to Pyongyang to avoid the risk of being attacked from two directions.

When Pyongyang was liberated, many Japanese prisoners of war boasted that Japanese had as many as 100,000 troops stationed in Hanseong. Nevertheless, Korean gentries, ever so eager to see their homeland liberated, kept on nagging the Ming army to attack immediately despite their knowledge of heavy Japanese presence at Hanseong. Even Ryu Seong-ryong (류성룡 or 柳成龍), Chief State Councillor of Joseon Kingdom, personally went to Imjin River to oversee the construction of pontoon bridge to facilitate the transportation of Ming equipment and cannons, despite the fact that such lowly work was beneath the dignity of his noble status. He also reported to the Ming that there were, at most, only 10,000 Japanese troops currently stationed in Hanseong, in stark contrast to the testimonials of Japanese prisoners. If Ryu Seong-ryong's report was true and Japanese only had 10,000 troops, then Ming could easily retake Hanseong with currently available troops. However if the testimonials of Japanese prisoners were accurate, then Ming army must consider retreating to Pyongyang and wait for reinforcement. As Ming army was still eager to fight after a string of victories, and there was no concrete intelligence on the enemy, Li Ru Song (李如松), commander-in-chief of Ming expeditionary force, decided to personally go to Imjin River to gather information. As a precaution, he ordered Gao Ce (高策) and Liang Xin (梁心) to rebuild the defence of Pyongyang with 3,000 men.

Li Ru Song arrived at Paju on 26 February 1593. He sent out a 3,000-strong scouting force to gather information about terrain and defence of Hanseong, but the scouting force encountered a forward sentry force under Ukita Hideie (宇喜多秀家) during the mission. The news of Ming arrival at the outskirt of Hanseong prompted the Japanese defenders to immediately mobilise their troops and prepare for war.

Early in the morning on 27 February 1593, Ming scouting force crossed Haeeumlyong hill, some 21.5 km away from Hanseong, and arrived at Byeokjegwan under the thick morning fog. A small skirmish broke out between Ming and Japanese scouts at around 2 am in the morning, although both sides quickly disengaged. Caught wind of the skirmish, Tachibana Muneshige marched his force out of the west gate and arrived at Yeoseoghyeon at around 6 am.

And thus began the Battle of Byeokjegwan.


The Battlefield

The original author used 'Haedong chido (해동지도 or 海東地圖)', an ancient Korean map, to reconstruct the battlefield. Unfortunately, I cannot find a high-resolution image of his map, so I replaced his image with a different edition of the same map. The complete image can be viewed here.

Located between Hanseong and Paju, Byeokjegwan (벽제관 or 碧蹄館) was a relay station used by Korean officials from Hanseong to receive Chinese delegates. It was about 5.89 km from Yeoseoghyeon (여석현 or 礪石峴) hill, itself about 11.78 km away from Hanseong. Byeokjegwan was built inside a valley at the southwestern side of Manggaeghyeon (망객현 or 望客峴) ridge, south of the 164 m high Haeeumlyong (혜음령 or 惠陰嶺) hill range. The valley is wider at the bottom than at the top, and spans roughly 3.927 km from north to south. It is around 327 m to 872 m in width. Numerous hills surround the valley from both sides, and a small stream, flowing from north to southwest, passes through the valley. Korean people traditionally grown rice along the stream.

Goyang can be found in a valley north-northwest of Byeokjegwan. At the time, it was but an unwalled town littered with various government buildings, houses and grain stores. At the east side of Byeokjegwan, there is a col in the Manggaeghyeon ridge. The road to Hanseong passed through the col from the north, headed southeast, crossed the stream from Hongbogsan (홍복산 or 洪福山), and split into two at two lone hills near Yeoseoghyeon hill. One of the split roads branched out before the lone hills and headed south. The other road passed between the lone hills, split into two again at Sinwonjeom (신원점 or 新院店), the area between the lone hills and Yeoseoghyeon, then headed south as well. All three routes passed through Yeoseoghyeon hill at different points, but all led to Hanseong.

A small plain, about 3.5 km to 4 km from east to west and 0.8 km to 1.8 km from north to south, lies between the south of Yeoseoghyeon hill and Changneung Royal Tomb. Cha Da Shou (查大受) scouted the area before Battle of Byeokjegwan took place, so the plain was already familiar to Ming army.

The battlefield reconstructed with Google Maps. The original author created these maps with Chinese labelling, but I recreated his maps in English.

Belligerents
Ming

Division	Commander	Strength
Ming Scouting Force	Vanguard Cha Da Shou (查大受) Go Eon-baek (고언백 or 高彥伯)	590 Kuandian Cavalry 100+ Korean Cavalry
	Sun Shou Lian (孫守廉) Zu Cheng Xun (祖承訓) Li Ning (李寧)	702 Shenyang Cavalry 700 Haizhou Cavalry 1,189 Liaodong Garrison Regular Corp Cavalry
TOTAL: 3,281+
Reinforcement (Leader: Li Ru Song)	Li Ru Song (李如松) Li Ru Bai (李如柏) Zhang Shi Jue (張世爵)	1,000 Retinue Cavalry
	Yang Yuan (楊元)	1,000 Ming Cavalry
TOTAL: 2,000

*Note: Yang Yuan's force only arrived at last minute to bail out other Ming forces.

It was clear from the start that Ming army only intended to mount an armed reconnaissance mission to Hanseong. Ming scouting force that arrived first was headed by Sun Shou Lian (孫守廉), Zu Cheng Xun (祖承訓) and Li Ning (李寧). Cha Da Shou served as the vanguard of the scouting force, with Korean commander Go Eon-baek (고언백 or 高彥伯) as his co-leader and local guide. Most of the troops of Ming scouting force were elites.

Ming reinforcement was headed by Li Ru Song himself, with Li Ru Bai (李如柏), Yang Yuan (楊元) and Zhang Shi Jue (張世爵) among others accompanying him. Li Ru Song later split his force into two and raced ahead of Yang Yuan.

While it is commonly believed that Li Ru Song did not bring any Southern troops to this battle due to bitter dissension between Northern and Southern Chinese troops, the reality was that a reconnaissance mission in unknown territory demanded specially selected and experienced troops. As most of the Southern troops were fresh recruits, they were simply not up to the task. After all, Hanseong was 39.27 km away from Paju. It would be very unreasonable to expect foot-slogging fresh recruits to march for nearly 80 km in a single day (a round trip), let alone keeping up with elite cavalry on such a dangerous mission.

Furthermore, as Koreans were incapable of providing adequate logistics support to Ming army, they wanted to force Ming army to advance south and end the war as quickly as possible. To this end, they decided to spread out what supply they could gather along the Ming army's march route. The decision proved disastrous, as Ming army was effectively prevented from concentrating its troops in one place for fear of exhausting local supply too quickly. In fact, Li Ru Song was forced to leave half his army behind when he crossed Imjin River for this very reason (Translator's Note: In other words, Li Ru Song was unable to muster a larger force for this battle even if he had wanted to).


Japanese

Division	Subdivision	Commander	Strength
First Division (Leader: Kobayakawa Hidekane)	1st Subdivision (Leader: Tachibana Muneshige)	Vanguard Ono Shigeyuki (小野鎮幸) Mitabi Shigehisa (米多比鎮久)	700+
		Middleguard Totoki Tsurehisa (十時連久) Uchida Munetsugu (内田統続)	500+, mostly cavalry
		Rearguard Tachibana Muneshige (立花宗茂) Takahashi Munemasu (高橋統増)	1,800+ Infantry 212 Cavalry
	2nd Subdivision (Leader: Kobayakawa Hidekane)	Left Vanguard Awaya Kagekatsu (粟屋景雄)	3,000
		Right Vanguard Inoue Kagesada (井上景貞)	3,000
		Kobayakawa Takakage (小早川隆景)	2,000
	3rd Subdivision	Kobayakawa Hidekane (小早川秀包) Suetsugu Motoyasu (末次元康) Tsukushi Hirokado (筑紫広門)	5,000
	4th Subdivision	Kikkawa Hiroie (吉川広家)	4,000
TOTAL: 20,212+
Second Division (Leader: Ukita Hideie)	1st Subdivision	Kuroda Nagamasa (黒田長政)	5,000
	2nd Subdivision	Ishida Mitsunari (石田三成) Mashita Nagamori (増田長盛) Ōtani Yoshitsugu (大谷吉継)	5,000
	3rd Subdivision	Katō Mitsuyasu (加藤光泰) Maeno Nagayasu (前野長康)	3,000
	4th Subdivision	Ukita Hideie (宇喜多秀家) Togawa Tatsuyasu (戸川達安)	8,000
TOTAL: 21,000
Hanseong Defence Force (Leader: Konishi Yukinaga)	-	Konishi Yukinaga (小西行長) Otomo Yoshimune (大友義統)	10,000
TOTAL: 10,000

*Note: Second division arrived late and did not actually participate in the battle. Hanseong Defence Force also did not join the battle for obvious reasons.

Japanese army divided its main force of 41,000 into two divisions. Tachibana Muneshige, renowned among his peers for his bravery (it was said that three thousand of his troops could go toe to toe with ten thousand troops of his peers), was chosen as the vanguard. At the time, he stationed his men at the west gate of Hanseong.

An additional 10,000-strong force led by Konishi Yukinaga and Otomo Yoshimune stayed behind to defend Hanseong.


The Battle

Initial deployment.

Cha Da Shou and Go Eon-baek probably moved slightly ahead of the rest of the Ming scouting force. When Tachiban Muneshige's force showed up at Yeoseoghyeon, Cha Da Shou's force had already took control of Manggaeghyeon ridge. Goyang and Byeokjegwan came under Ming-Joseon control as well, as there were Korean officials trying to requisition supply from those places at the time. Totoki Tsurehisa (十時連久) led 500 men and moved ahead of Tachibana Muneshige's force, arriving at the two lone hills about 2,180 m away from Cha Da Shou's force. Ono Shigeyuki (小野鎮幸) led 700 men and followed closely behind Totoki Tsurehisa.

At around 7 am, Ming cavalry made its move and engaged Totoki Tsurehisa's force. As soon as both sides made contact, Totoki Tsurehisa mustered his cavalry and charged Ming cavalry. Ming cavalry did not meet his charge head on, but withdrew towards Manggaeghyeon almost immediately. As shown on the following battle maps, Totoki Tsurehisa's force moved northwest in pursuit of Ming cavalry into a bowl-shaped area near Manggaeghyeon col, which exposed his entire right flank to the Ming's left wing.

Cha Da Shou and Go Eon-baek made contact with Totoki Tsurehisa.

Cha Da Shou and Go Eon-baek retreated towards Manggaeghyeon.

As Totoki Tsurehisa's force came within several hundred metres of Manggaeghyeon, the rest of the Ming scouting force showed up at the northeast of Totoki Tsurehisa's force, then launched a combined arms attack with cavalry charge and artillery shelling to his right flank in order to cut him off from Ono Shigeyuki's force. The withdrawing Ming cavalry also turned around and attacked his front. This was the first combat of Battle of Byeokjegwan. Totoki Tsurehisa's force suffered heavy losses in his failed attack (Translator's Note: In fact, Totoki Tsurehisa himself was wounded in battle and died shortly after), with Cha Da Shou reportedly taken one hundred and thirty heads. Cha Da Shou then proceeded to report the news of his victory to Li Ru Song at Paju. After receiving the news, Li Ru Song rode out with his retinues to Byeokjegwan to personally access the situation.

Suffering heavy casualties due to being attacked from two directions, Totoki Tsurehisa retreated towards Ono Shigeyuki's force. Tachibana Muneshige's main force of 2,000 men proceeded to move out from Sinwonjeom's left hill to engage the Ming's right wing, and both armies engaged in intense combat. Unfortunately, Tachibana Muneshige's main force only had 212 cavalry, while Ming scouting force consisted of mounted troops in its entirely. As the battle was fought on flat terrain, Tachibana Muneshige's force was greatly disadvantaged and suffered heavy losses as well, forcing him to retreat back to the lone hills of Sinwonjeom. By utilising the narrow hill pass to his advantage, Tachibana Muneshige mustered some 200 arquebuses to slow down the relentless Ming assault.

Totoki Tsurehisa's force was attacked from several directions.

Totoki Tsurehisa's force suffered heavy casualties and retreated.

Ming scouting force engaged Tachibana Muneshige's main force.

Tachibana Muneshige retreated into the lone hills.

At around 10 am, Kobayakawa Takakage (小早川隆景) and the rest of Japanese first division arrived at the battlefield. His left and right vanguard, Awaya Kagekatsu (粟屋景雄) and Inoue Kagesada (井上景貞), each with 3,000 men, proceeded to relieve the bloodied Tachibana Muneshige's force and spread out along Yeoseoghyeon hill. As Japanese force quickly swelled to 12,000 ~ 15,000 troops, the now-outnumbered Ming scouting force decided to disengage and withdraw towards the direction of Byeokjegwan. They returned to the bowl-shaped area near Manggaeghyeon col, and both sides entered a standoff.

At the same time, Li Ru Song's force had arrived at Haeeumlyong. He met some retreating Go Eon-baek's officers en route, and was informed of the arrival of Japanese reinforcement. Li Ru Song decided to immediately rush ahead to Byeokjegwan with only half his men. In the hurry, Li Ru Song accidentally fell from his horse and injured himself, but he immediately switched horse and continued his march.

Kobayakawa Takakage arrived at the scene.

Both sides entered a standoff. Li Ru Song arrived at the scene.

It should be noted that by this time, Japanese forced had occupied most of the the hills and valleys surrounding the eastern and middle routes that passed through Yeoseoghyeon. Both of these routes were long and narrow, as even the shorter of the two was still about 2 km in length through the hill, and only 20 m in width at the narrowest point. On the other hand, the western route that split before lone hills was built on flatter ground, and passed Yeoseoghyeon hill through a relatively short, 500 m long hill pass. Judging from the terrain and deployment of both armies, Li Ru Song probably planned to take to the western route by force and bypass the Yeoseoghyeon hill occupied by the Japanese. If his plan was successful, it could put Li Ru Song's force on the favourable small plain directly at the rear of Japanese force, essentially trapping the entire Japanese force on Yeoseoghyeon hill. Even if Japanese force retreated before Li Ru Song was able to bypass Yeoseoghyeon hill, their entire left flank would still be exposed to attack.

Li Ru Song's plan.

Unfortunately, Li Ru Song's plan seriously underestimated just how many troops the Japanese military leaders were willing to mobilise to defeat a mere scouting force. He was clearly inclined to agree with Korean report (of about 10,000 Japanese troops) over Japanese prisoners' testimonials, and calculated that even if Korean report was inaccurate, it shouldn't be too far off the mark — the Japanese couldn't have spared too many troops to Yeoseoghyeon hill as they still had an important city to defend. The rapid collapse of Japanese front line following the Siege of Pyongyang only served to strengthen this belief. In truth, the rapid shrinking of Japanese battle-line was probably caused by serious Japanese overestimation of the actual strength of Ming force following their defeat at Pyongyang, as chaos that ensued after the defeat had make intelligence gathering all but impossible. Besides, Japanese forces were slowly running out of supply. These factors caused the Japanese military leaders to act overly paranoid, so they decided to consolidate to Hanseong in anticipation of a major offensive from a numerically superior Ming force (that didn't actually exist).

Thus, both sides acted under serious miscalculation due to inadequate intelligence. Ming force seriously underestimated Japanese strength, which led to them launching a foolhardy attack against Japanese force despite being under unfavourable terrain and seriously outnumbered. On the other hand, Japanese force clearly overestimated Ming strength. This led to a major overreaction and mobilisation of nearly all of its available troops. With all that said, battlefield advantage was clearly with the Japanese, as they now enjoyed overwhelming numerical superiority and occupied favourable terrain close to their home base.

When Li Ru Song decided to make his move towards western route, Ming force was already seriously outnumbered. Discounting Tachibana Muneshige's force that suffered heavy losses, Japanese still had about 17,000 troops present. In fact, Awaya Kagekatsu and Inoue Kagesada alone brought more troops (6,000 men) than the entire Ming force. In contrast, Ming scouting force was weary after several hours of intense combat, and only received 1,000 fresh reinforcement from Li Ru Song.

The battle renewed. Li Ru Song personally led his elite retinue cavalry, consisted of his most trusted retainers and bodyguards, and attacked Awaya Kagekatsu's 3,000-strong force that was deployed along the western side of Yeoseoghyeon. Li Ru Song's retinue cavalry blasted at Awaya Kagekatsu's force with Shen Ji Jian (神機箭) rockets, which prompted Awaya Kagekatsu to order his arquebusiers to the front to return fire. However, Li Ru Song's retinue cavalry swiftly charged into close combat. Unable to resist the cavalry charge, Awaya Kagekatsu retreated into Yeoseoghyeon hill.

Li Ru Song attacked Awaya Kagekatsu.

Unexpectedly, this led Li Ru Song's retinue cavalry to pursue into a bowl-shaped area at Yeoseoghyeon hill as well, exposing his left flank to Japanese attack. Ming force was immediately given a taste of its own medicine, as Inoue Kagesada's force attacked Li Ru Song's left flank from Sinwonjeom, while Awaya Kagekatsu's force turned around and attacked Li Ru Song's front. Li Ru Song's force was now attacked by enemies six times its size.

To prevent other Ming forces to come to Li Ru Song's aid, Kobayakawa Takakage ordered Kobayakawa Hidekane (小早川秀包), Suetsugu Motoyasu (末次元康) and Tsukushi Hirokado (筑紫広門) to attack Ming scouting force from the right side of Sinwonjeom's hills with their 5,000-strong forces. He personally led his own men to replace Awaya Kagekatsu's force, while Tachibana Muneshige's remnants took the place of Inoue Kagesada's force. As both of them kept Li Ru Song occupied, Awaya Kagekatsu and Inoue Kagesada marched north towards the outskirts of Goyang in an attempt to encircle the Ming force from west of Byeokjegwan. Realising that they were badly outnumbered, Li Ru Song ordered his troops to retreat towards Manggaeghyeon ridge, and personally stayed behind to cover their retreat. As Ming forces were retreating, Yang Yuan's force arrived at the nick of time and met Li Ru Song's force. He proceeded to block off Manggaeghyeon col to deter pursuit. At the same time, Ukita Hideie's vanguard, Togawa Tatsuyasu (戸川達安), also arrived at Yeoseoghyeon with his troops. As fresh Japanese reinforcement kept arriving and Ming was unable to prevent Japanese encirclement, Li Ru Song decided to give up on Byeokjegwan. He discarded his force's supply to blockade the road, then retreated to Paju.

Li Ru Song was attacked from two directions. At the same time, Kobayakawa Hidekane, Suetsugu Motoyasu and Tsukushi Hirokado attacked Ming scouting force.

Awaya Kagekatsu and Inoue Kagesada marched north to encircle Ming forces. Yang Yuan arrived at the scene.

Ming forces retreated to Paju.

Thus ended the Battle of Byeokjegwan, a hastily conducted encounter battle.

The original author criticised this battle map for its inaccuracies and factual errors. For completeness sake, I also included it in my translated version. 

Translator's Remark
It should be noted that many samurai changed their names several times throughout their lives due to various reasons such as adoption into a different clan, switching allegiance, marriage, and so on. For the purpose of this article, I choose to use the most recognisable names for these samurai, rather than period-accurate names.

A good example of this frequent name change is best illustrated by famous samurai Tachibana Muneshige (立花宗茂), who changed his name fourteen times throughout his life (once posthumously). In fact, the name Tachibana Muneshige, although most recognisable, was only adopted during his old age. Additionally, while it might not be immediately apparent, Takahashi Munemasu (高橋統増) was actually Tachibana Muneshige's younger brother by blood. Later in his life he also changed his name to Tachibana Naotsugu (立花直次).



Other blog posts in my translated Battle of Byeokjegwan series:

The Battle of Byeokjegwan — Part 1

The Battle of Byeokjegwan — Part 2
Extra: List of named casualties (Patreon post)