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Battle of Chosin (Jangjin) Reservoir
November 27 – December 13, 1950· Battle· Wars & invasions
Well documentedSolid records, physical evidence or scientific consensus.
A 17-day battle in brutal cold in which about 30,000 UN troops broke out of a Chinese encirclement in northeast Korea.
See it on the Korean History map →What happened
On November 27, 1950, Chinese forces of the 9th Army Group, roughly 120,000 men (estimates vary), surrounded US Marines, US Army units and British commandos at Jangjin Reservoir (장진호), known to Americans by its Japanese reading, Chosin. In temperatures near −30°C, UN troops fought their way about 125 km south to the port of Hungnam. Army units east of the reservoir were nearly destroyed, and frostbite crippled both sides.
Why it matters
It saved the UN force in the northeast but ended the drive to the Yalu, and it led directly to the Hungnam evacuation of soldiers and refugees.
How we know
US Marine Corps and Army histories, Chinese military histories, unit diaries and veterans' accounts; the American survivors call themselves the 'Chosin Few.'
Still debated
Both sides claim success: the US calls it a fighting withdrawal, China a victory. Chinese losses, many from cold, remain uncertain; estimates vary widely.
Connections (2)
▸Chinese entry into the Korean War triggered Battle of Chosin (Jangjin) ReservoirWell documented
The connection
After first clashes in late October the Chinese pulled back, and UN commanders, doubting their numbers, launched a 'home by Christmas' offensive on November 24. China's second offensive struck days later; in the northeast its 9th Army Group, about 120,000 men (estimates vary), encircled roughly 30,000 UN troops around the reservoir.
When and how
Jangjin Reservoir, northeast Korea, from November 27, 1950; the US 1st Marine Division, US Army units and British commandos against Song Shilun's 9th Army Group.
How we know
US and Chinese military histories describe the same operation in detail, though their casualty claims differ widely.
Debates and open questions
Why UN commanders discounted clear signs of a massive Chinese presence after the October clashes is still debated.
▸Battle of Chosin (Jangjin) Reservoir was among the hardest battles of Korean WarWell documented
The connection
In 17 days of fighting near −30°C, UN troops broke out about 125 km to the coast. They escaped, but the northeast was abandoned: by December 24 the Hungnam evacuation had shipped out about 100,000 troops and about 100,000 civilian refugees. Cold and combat left China's 9th Army Group out of action for months.
When and how
Northeast Korea, November–December 1950; the Hungnam evacuation of December 15–24 included the freighter SS Meredith Victory, which carried about 14,000 refugees.
How we know
Unit records, veterans' accounts and Chinese histories; Guinness lists the Meredith Victory's voyage as the largest rescue by a single ship.
Debates and open questions
Whether MacArthur's choice to run X Corps separately from the Eighth Army, with a mountain gap between them, set up the defeat in the northeast is still argued.