The Third Battle of Seoul: A Turning Point in the Korean War
In the freezing winter of 1950, the Korean War entered a volatile new phase. Following the massive intervention of Chinese forces, the United Nations (UN) front lines were pushed back in a series of rapid retreats. One of the most significant engagements during this period was the Third Battle of Seoul, a week-long struggle from December 31, 1950, to January 7, 1951, that resulted in the temporary recapture of the South Korean capital by communist forces.
Key Facts
- Date: December 31, 1950 – January 7, 1951
- Location: Seoul, South Korea
- Outcome: Victory for the People's Volunteer Army (PVA) and North Korean forces
- Primary Combatants: UN forces (US, UK, Australia, Thailand, South Korea) vs. China and North Korea
- Key Result: The evacuation of Seoul by UN forces on January 3, 1951
Historical Context and Background
By late 1950, the conflict had shifted dramatically. After the UN offensive into North Korea, the People's Volunteer Army (PVA)—the Chinese military force supporting North Korea—launched a massive counter-offensive. This forced UN troops to retreat from North Korean territory throughout December.
On the western front, the US Eighth Army was attempting to stabilize its positions along the 38th Parallel (the line of latitude that roughly divides North and South Korea). Following the death of Eighth Army commander General Walton Walker in a traffic accident on December 23, Lieutenant General Matthew B. Ridgway assumed command. Ridgway faced a difficult task: managing a force with low morale and preparing defenses to protect Seoul from the advancing Chinese threat.
Forces and Strategic Objectives
The battle was characterized by a significant disparity in troop readiness. While the UN forces were attempting to organize a defensive line, many of the Republic of Korea (ROK) units were composed of raw recruits with limited combat training. Conversely, the Chinese leadership, led by Mao Zedong and Peng Dehuai, planned a targeted offensive known as the Third Phase Campaign.
Mao's strategy was to pin down ROK forces along the 38th Parallel and inflict maximum damage. The PVA planned to launch their assault on December 31, utilizing the cover of a full moon and the holiday season to catch UN soldiers at a moment of low alertness.
The Defensive Lines
Before the attack, the Eighth Army had established several defensive sectors:
- US I Corps: Tasked with defending the Imjin River.
- US IX Corps: Tasked with defending the Hantan River.
- ROK III Corps: Tasked with guarding the areas around Chuncheon.
To prepare for a potential retreat, Ridgway ordered the creation of the Bridgehead Line, a defensive position stretching from Koyang to Uijeongbu, intended to cover Han River crossings.
The Collapse of the 38th Parallel
On the night of December 31, 1950, the PVA 13th Army launched a massive assault. The ROK 1st and 6th Infantry Divisions, along with the ROK III Corps, bore the brunt of the attack. The Chinese "thrust" companies—specialized assault and engineer teams—successfully breached the defenses at the Imjin and Hantan Rivers.
The battle at the Imjin River was particularly chaotic. Due to intelligence errors, some PVA units mistakenly attacked the US 19th Infantry Regiment instead of the intended ROK units. Despite suffering heavy casualties from minefields and US resistance, the PVA pushed through, exposing the flanks of the ROK 6th Division and forcing them into a full retreat. By the morning of January 1, the UN defenses at the rivers had effectively collapsed.
The Fall of Chuncheon
Simultaneously, in the Chuncheon sector, the PVA 42nd and 66th Corps struck the ROK III Corps. They successfully cut the road between Chuncheon and Seoul, trapping several ROK regiments. The ROK 2nd and 5th Infantry Divisions were forced into disarray, with many soldiers forced to escape through difficult mountain trails to avoid encirclement.
The Evacuation of Seoul
Recognizing that the defenses had been breached and fearing a total encirclement of the Eighth Army, General Ridgway ordered the evacuation of Seoul on January 3, 1951. The withdrawal was a massive undertaking involving multiple corps and international units.
The retreat was not without resistance. As US and British units moved toward the Bridgehead Line, they faced fierce hand-to-hand combat. The British 29th Independent Infantry Brigade and the 27th British Commonwealth Brigade played critical roles in covering the withdrawal of the US IX Corps. By the morning of January 4, the last tactical UN units, including the US 27th Infantry Regiment, had crossed the Han River.
When the PVA and North Korean forces entered Seoul on the afternoon of January 4, they found a city largely emptied of its population. Most civilians had already fled across the frozen Han River or into the countryside. The North Korean flag was raised at Seoul City Hall that afternoon.
Summary of Combatant Strength and Losses
| Category | United Nations (UN) | China / North Korea |
|---|---|---|
| Total Strength | ~136,525 | ~170,000 |
| Major Units | US I & IX Corps, ROK III Corps, British 29th Bde | PVA 13th Army, KPA I Corps |
| Casualties | ~481 (US 24th/25th Div) | ~8,500 (China: ~5,800; NK: ~2,700) |
Frequently Asked Questions
Why did the UN forces decide to evacuate Seoul?
General Ridgway ordered the evacuation because the Chinese breakthrough at the Imjin and Hantan Rivers threatened to encircle the entire Eighth Army. He lacked confidence that the remaining UN troops could hold the city against the massive PVA offensive.
What role did the weather play in this battle?
The weather was extreme; the Han River was frozen, which allowed refugees to stream across the ice to escape the city. Additionally, the cold conditions and the timing of the attack during the holiday season were factors in the tactical movements of both sides.
How did the Chinese forces manage to break the ROK defenses?
The PVA used specialized "thrust" companies consisting of trained assault and engineer teams. They also utilized night assaults under a full moon to minimize the effectiveness of UN air and artillery support.
Who was the last UN unit to leave Seoul?
The US 27th Infantry Regiment was the last tactical UN unit to remain in the city, eventually crossing the Han River on the afternoon of January 4, 1951.
How long did the Chinese occupation of Seoul last?
The occupation began on January 4, 1951, when the city was found empty. The Chinese offensive was halted by January 7 due to troop exhaustion and the need to prevent a repeat of the Incheon landings.