Coordinates: 39°58′20″N 125°48′12″E / 39.97222°N
125.80333°E / 39.97222; 125.80333 (Unsan)
Battle of Unsan
Part of the Korean War
Map of Battle of
Unsan on the night of 1 – 2 November 1950
25 October – 4 November 1950
Unsan, North Korea
Commanders and leaders
Frank W. Milburn
Raymond D. Palmer
Paik Sun Yup
39th Corps[nb 1]
1st Cavalry Division
5th Cavalry Regiment
8th Cavalry Regiment
1st Infantry Division
15th Infantry Regiment
Casualties and losses
UN estimation: 600+
1,149 total casualties
South Korea: 530
Chinese estimation: 2,000
North Korean Offensive
1st Naktong Bulge
2nd Naktong Bulge
UN Command Counteroffensive
12 October 1950
Task Force Faith
1st and 2nd Wonju
Ripper (4th Battle of Seoul)
1st Maryang San
2nd Maryang San
Pork Chop Hill
Korean Armistice Agreement
The Battle of
Unsan (Hangul: 운산전투;
Hanja: 雲山戰鬪; RR:
Unsan jeontu; MR: Unsan
chŏnt'u), also known as the Battle of Yunshan (Chinese: 云山战斗;
pinyin: Yún Shān Zhàn Dòu), was a series of engagements of the
Korean War that took place from 25 October to 4 November 1950 near
North Pyongan province in present-day North Korea. As part of
the Chinese First Phase Campaign, the People's Republic of China's
People's Volunteer Army
People's Volunteer Army made repeated attacks against the Republic of
Korea 1st Infantry Division near
Unsan beginning on 25 October, in an
attempt to take advancing
United Nations forces by surprise. In an
accidental first encounter with the
United States military during the
Korean War, the Chinese 39th
Corps attacked the unprepared US 8th
Cavalry Regiment in
Unsan on 1 November, resulting in one of the most
devastating US losses of the Korean War.
2.1 Locations and terrain
2.2 Forces and strategy
3.1 Initial skirmish
3.2 Chinese counterattack
7 External links
By October 1950, the
United Nations (UN) forces had successfully
broken out of the Pusan Perimeter in the extreme south of Korea and
begun an northward advance towards the Sino-Korean border, chasing the
Korean People's Army
Korean People's Army (KPA). The US 1st Cavalry
Pyongyang on 19 October, while the Republic of
Korea Army (ROK) were rushing towards the
Yalu River in all
directions. As part of the Thanksgiving Offensive to end the war,
Major General Frank W. Milburn, commander of the US I Corps, ordered
the ROK 1st Infantry Division to secure the
Sup'ung Dam on the Yalu
River by advancing through Unsan.
Alarmed by the rapid collapse of the KPA, China's Chairman Mao Zedong
ordered the People's Liberation Army's North East Frontier Force to be
reorganized into the
People's Volunteer Army
People's Volunteer Army (PVA) for the upcoming
intervention in Korea. Despite Mao's determination to save North
Korea from capitulation, the Chinese military leadership expressed
doubts on the ability of the Chinese army to fight against the more
modernized US forces. As a compromise, Mao authorized the First
Phase Campaign, a bridgehead building operation with limited
offensives against only the South Korean forces while avoiding
contacts with the US forces. Under strict secrecy, the PVA
entered Korea on 19 October.
Locations and terrain
Unsan is a town in northwest Korea, and it is located 50 mi
(80 km) from the
Ch'ongch'on River mouth on the Korean west
coast.:672 Because of the hilly terrains at the Sino-Korean Border,
Unsan is one of the few access points into the
Yalu River area.:673
The town is surrounded by hills to the north, the Nammyon River to the
west and the Samtan River to the east. At the south of the town, a
road junction controls the road from
Unsan to Ipsok while a ridge
dubbed "Bugle Hill" controls the road between
Unsan and Yongsan-dong.
Those two roads formed the only retreat routes for the UN forces at
Forces and strategy
Acting on Milburn's instruction, the ROK 1st Infantry Division
advanced north on 24 October with the ROK 6th Infantry Division on its
right and the US 24th Infantry Division on its left, and by the
morning of 25 October, the ROK 1st Infantry Division had captured
Unsan. But with the UN forces spread thinly across Korea, a
15 mi (24 km) gap was left between the US 24th Division and
ROK 1st Division, leaving the Korean left flank unprotected.:680
Upon noticing the thinly held UN frontline, the Chinese decided to
launch a pincer movement against the South Koreans at Unsan. As part
of the First Phase Campaign, the PVA 120th Division of the 40th Corps
was at first to block and hold the ROK 1st Infantry Division at
Unsan. Simultaneously, the bulk of the 40th Corps, together with
the PVA 38th
Corps and one division from the 42nd Corps, would attack
and destroy the ROK 6th and 8th Infantry Divisions at the east of
Unsan. Finally, the PVA 39th
Corps would destroy the ROK 1st
Infantry Division by infiltrating the gap between US 24th Division and
the ROK 1st Infantry Division west of Unsan. Undetected by UN
intelligence, the 120th Division arrived at the blocking position on
24 October, with its 360th Regiment heavily fortified the hills north
of Unsan. To obscure troop movements and to prevent UN air raids,
the Chinese also started several forest fires around the end of
On 25 October at 10:30, the ROK 1st Infantry Division attacked north
with its 12th Regiment on the western bank of Samtan River while the
15th Regiment was trying to reach the eastern bank. But when the
15th Regiment was about to cross the river, the PVA 120th Division
intercepted the South Koreans with heavy artillery fire. The South
Koreans first believed the resistance to be the last remnants of the
KPA, but the perception soon changed with the capture of the first
Chinese prisoner in the Korean War. The prisoner revealed that
there were 10,000 Chinese soldiers waiting to join the fight north of
Faced with the sudden appearance of the overwhelming Chinese forces,
the ROK 1st Infantry Division tried to establish defensive positions
by capturing the hills around Unsan. The South Koreans soon found
themselves in a seesaw battle with the PVA 360th Regiment during the
night of 25 October. The next day, the PVA 39th
at the west of
Unsan while cutting the road between
Yongsan-dong, completely surrounding the ROK 1st Infantry
Division. Aided by airdrops, the US 6th Medium Tank Battalion and
the US 10th Anti-Aircraft Artillery Group, the ROK 1st Infantry
Division reopened the road on 27 October.:678 Several more attempts
to advance north by the Koreans made little progress,:678 and the
fighting stopped by 28 October.
Despite the warnings given by
Brigadier General Paik Sun Yup,
commander of the ROK 1st Infantry Division,:678 a general feeling
of optimism about the outcome of the war prevented the warnings from
being taken seriously. With the fighting reached a stalemate at
Walton Walker of the Eighth
United States Army ordered
the US 8th Cavalry Regiment of the US 1st Cavalry Division to resume
offensives north by relieving the ROK 12th Regiment. By the time
the US 8th Cavalry Regiment reached
Unsan on 29 October, the ROK 11th
Infantry Regiment of the ROK 1st Infantry Division was also pulling
out of Unsan.:681 At the same time, the Chinese had destroyed the
ROK 6th Infantry Division on the east of Unsan.
Unsan had now
became a northern salient in the UN line containing only the US 8th
Cavalry Regiment and the ROK 15th Infantry Regiment.:680
Still believing that the ROK 1st Infantry Division was tied up at
Unsan, PVA Commander
Peng Dehuai gave the go ahead for the 39th
Corps to destroy the
Unsan garrison on 1 November. The Chinese
plan called for the PVA 117th Division to attack from the northeast,
the 116th Division to attack from the northwest and the 115th Division
to attack from the southwest. At the same time, the US 8th Cavalry
Regiment had taken up positions around the town, with its 1st
Battalion defending the north of
Unsan by the Samtan River, while its
2nd and 3rd Battalions defending the areas west of the
Unsan by the
Nammyon River. The lack of UN manpower, however, created a
1 mi (1,600 m) gap between the 1st and 2nd
Battalions.:694 The ROK 15th Infantry Regiment, on the other hand,
had dug in northeast of the Unsan, across the river from the US 1st
In the early afternoon of 1 November, a combat patrol from the US 5th
Cavalry Regiment, rear guard of the 8th Cavalry Regiment, was
intercepted by PVA 343rd Regiment of the 115th Division at Bugle
Hill.:691 With the trap discovered, the Chinese immediately
launched their attacks at 17:00.:692 Supported by rocket
artillery,:692 the 117th Division attacked the ROK 15th
Infantry Regiment in full force while four Chinese battalions from the
116th Division struck the gap between the 1st and 2nd Battalions of
the US 8th Cavalry Regiment.:694 By 23:00, the heavy fighting
destroyed the ROK 15th Infantry Regiment while the US 1st and 2nd
Battalions were running out of ammunition.:694–5 As the UN forces
began to buckle around Unsan, Milburn finally ordered the garrison to
withdraw after learning the destruction of the ROK 6th Infantry
Division on the right flank.:695
Before the withdrawal could be carried out, however, the PVA 347th
Regiment of the 116th Division had already entered the town of Unsan
through the gap between the American battalions. Soon afterward,
several roadblocks appeared behind the US 1st and 2nd
Battalions.:696–7 With the attacks gaining momentum, the PVA
348th Regiment of the 116th Division advanced southward from
Unsan, ambushing the UN forces at the road junction by
02:30.:698–700 With all the roads blocked, the US 8th Cavalry
Regiment's 1st and 2nd Battalions had to escape by infiltrating the
Chinese lines in small groups, abandoning most of their vehicles
and heavy weapons along the way.:700 The surviving US and ROK
soldiers reached UN lines by 2 November.:700
While the US 8th Cavalry Regiment's 1st and 2nd Battalions were under
heavy attack, its 3rd Battalion was left alone for most of the
night,:701 but by 03:00, a company of Chinese commandos from the
116th Division managed to infiltrate the battalion command post
disguised as ROK soldiers.:702 The following surprise attack
set many vehicles on fire while causing numerous casualties among the
Americans,:78–9 most of whom were still sleeping.:702 By the
time the confusing fighting had ended, the 3rd Battalion was squeezed
into a 200 yd (180 m) wide perimeter by the PVA 345th
Regiment of the 115th Division.:704 The US 5th Cavalry Regiment
made repeated attempts to rescue the 3rd Battalion by attacking the
PVA 343rd Regiment at Bugle Hill, but after suffering 350
casualties, the 5th Cavalry was forced to withdraw under orders from
Major General Hobart Gay, commander of the US 1st Cavalry
Division.:704 The trapped 3rd Battalion endured days of constant
attacks, and the surviving soldiers managed to break out of the
perimeter by 4 November.:707–8 By the end of the battle, less
than 200 survivors from the 3rd Battalion managed to return to the UN
Immediately after the success at Unsan, the rest of the Chinese forces
advanced across the US lines, intending to push the US forces back
Ch'ongch'on River and into Pyongyang. But food and
ammunition shortages soon forced the Chinese to disengage on 5
November, thus ending the Chinese First Phase Campaign. Besides
the victory at Unsan, the Chinese First Phase Campaign also destroyed
the ROK 6th Infantry Division and one regiment from the ROK 8th
Infantry Division at the Battle of Onjong. In return, the
Chinese had suffered 10,700 casualties by the end of the Chinese First
Phase Campaign. The Battle of
Unsan has been considered to be one
of the most devastating US losses of the Korean War.
The Chinese victory at
Unsan was as much of a surprise to the Chinese
leadership as it was to the UN forces. The accidental encounter
between the Chinese and US forces at
Unsan eased the fear of the
Chinese leadership about intervening in Korea, while the
performance of the US 1st Cavalry Division was studied in great detail
by Chinese commanders. For the UN forces, on the other hand,
despite the heavy losses suffered by the US Eighth Army at Unsan, the
unexpected Chinese withdrawal made the
United Nations Command believe
China did not intervene in Korea on a large scale. PVA
Peng Dehuai incorporated the lessons from
Unsan for the
upcoming Second Phase Campaign, while General Douglas MacArthur
Home-by-Christmas Offensive under the assumption that
only a weak Chinese force was present in Korea, resulting in the
decisive battles at the
Ch'ongch'on River and the Chosin Reservoir
later that year.
^ In Chinese military nomenclature, the term "Army" (军) means Corps,
while the term "Army Group" (集团军) means Army.
^ a b Chinese Military Science Academy 2000, p. 359.
^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab Applemen,
Roy (1992). South to the Naktong, North to the Yalu. Center of
United States Army. ISBN 0160359589.
^ McMichael 1987, p. 69.
^ Ecker 2005, p. 47
^ Chae, Chung & Yang 2001, p. 124.
^ a b Chinese Military Science Academy 2000, p. 35.
^ a b c d Ryan, Finkelstein & McDevitt 2003, p. 127.
^ Millett, Allan R. (2009). "Korean War". Encyclopædia Britannica.
Archived from the original on 29 December 2008. Retrieved 4 February
^ Alexander 1986, p. 250
^ Roe 2000, p. 156.
^ Chae, Chung & Yang 2001, p. 114.
^ Roe 2000, p. 145.
^ Roe 2000, p. 146.
^ Roe 2000, p. 150.
^ Roe 2000, pp. 145, 148–149.
^ Alexander 1986, p. 273.
^ a b Chae, Chung & Yang 2001, p. 116.
^ a b c Chinese Military Science Academy 2000, p. 20.
^ Chinese Military Science Academy 2000, p. 21.
^ Chae, Chung & Yang 2001, pp. 116–117.
^ a b Chae, Chung & Yang 2001, p. 117.
^ a b c Chae, Chung & Yang 2001, p. 118.
^ Chinese Military Science Academy 2000, p. 22.
^ Chinese Military Science Academy 2000, p. 24.
^ Chae, Chung & Yang 2001, p. 119.
^ Halberstam 2007, pp. 9–44.
^ a b Chae, Chung & Yang 2001, p. 120.
^ a b Roe 2000, p. 168.
^ a b c Chinese Military Science Academy 2000, p. 32.
^ Alexander 1986, pp. 271, 273.
^ a b c d Chinese Military Science Academy 2000, p. 33.
^ a b Chinese Military Science Academy 2000, p. 34
^ Alexander 1986, p. 276
^ a b Mahoney, Kevin (2001). Formidable Enemies : The North
Korean and Chinese Soldier in the Korean War. Presidio Press.
p. 78. ISBN 9780891417385.
^ a b Roe 2000, p. 176.
^ Alexander 1986, p. 288.
^ Chinese Military Science Academy 2000, p. 44.
^ Przybyciel, Nick (3 March 2005). "The Battle of Unsan". Air Force
Reserve Command. Archived from the original on 7 June 2011. Retrieved
7 September 2009.
^ Roe 2000, p. 229.
^ Roe 2000, p. 230.
^ Roe 2000, p. 207.
^ Roe 2000, p. 233.
^ Roe 2000, p. 224.
^ Alexander 1986, pp. 312, 313
Alexander, Bevin R. (1986), Korea: The First War We Lost, New York,
NY: Hippocrene Books, Inc, ISBN 978-0-87052-135-5
Appleman, Roy (1992), South to the Naktong, North to the Yalu,
Washington, D.C.: Center of Military History,
United States Army,
Chae, Han Kook; Chung, Suk Kyun; Yang, Yong Cho (2001), Yang, Hee Wan;
Lim, Won Hyok; Sims, Thomas Lee; Sims, Laura Marie; Kim, Chong Gu;
Millett, Allan R., eds., The Korean War, Volume II, Lincoln, NE:
University of Nebraska Press, ISBN 978-0-8032-7795-3
Chinese Military Science Academy (2000), History of War to Resist
America and Aid Korea (抗美援朝战争史) (in Chinese), Volume II,
Beijing: Chinese Military Science Academy Publishing House,
Ecker, Richard E. (2005), Korean Battle Chronology: Unit-by-Unit
United States Casualty Figures and Medal of Honor Citations,
Jefferson, North Carolina: McFarland, ISBN 0-7864-1980-6
Halberstam, David (2007), The Coldest Winter - America and the Korean
War, New York: Hyperion, ISBN 978-1-4013-0052-4
Mahoney, Kevin (2001), Formidable Enemies : The North Korean and
Chinese Soldier in the Korean War, Novato, CA: Presidio Press,
McMichael, Scott R. (1987), "Chapter 2: The Chinese Communist Forces
in Korea" (PDF), A Historical Perspective on Light Infantry, Fort
Leavenworth, KS: US Army Combined Arms Center,
ISSN 0887-235X part 2
Roe, Patrick C. (2000), The Dragon Strikes, Novato, CA: Presidio,
Ryan, Mark A.; Finkelstein, David M.; McDevitt, Michael A. (2003),
Chinese Warfighting: The PLA Experience Since 1949, Armonk, New York:
M.E. Sharpe, ISBN 0-7656-1087-6
Unsan Unhinged - AccessMyLibrary
The Chinese Appraise Their First Phase Korean Action -