The 'Battle of Yenangyaung' was a battle between the British and Chinese defence and the Japanese aggressor forces for Yenangyaung during the Japanese 'B' (iii) invasion of Burma (11/19 April 1942).
After the Japanese had taken Rangoon on 8 March 1942, the Allies regrouped in central Burma. The newly formed Burma Corps, commanded by Lieutenant General W. J. Slim and comprising British, Indian and locally raised Burmese troops, attempted to defend the Irrawaddy river valley, while Lieutenant General Lin Wei’s Chinese Expeditionary Force in Burma defended the Sittaung and Salween river valleys farther to the east. After they had taken Singapore and captured the Netherlands East Indies, the Japanese were able to use divisions released by these successes, and also captured trucks to reinforce their army in Burma and launch attacks into central Burma.
One of the Japanese objectives in the Irrawaddy river valley was the Yenangyaung and its oilfields. The battle for the oilfields started on 10 April and continued for a week. The Japanese attacked Major General J. B. Scott’s 1st Burma Division on the Allied right and Brigadier N. Hugh-Jones’s Indian 48th Brigade at Kokkogwa at night in a storm and were repulsed with heavy casualties. On the following day, the 2nd Royal Tank Regiment was in action near Magwe at Thadodan and Alebo. Between 13 and 17 April, the British fell back under attacks by the Japanese. On several occasions Japanese roadblocks split the Burma Frontier Force (an internal security force acting as infantry), the 1st Burma Division, the headquarters of Brigadier J. H. Anstrice’s British 7th Armoured Brigade and the 2nd Royal Tank Regiment into three forces.
On 15 April, Slim ordered the demolition of he oilfields and refinery. The situation became so critical that General Sir Harold Alexander, commanding the Burma Army, asked Lieutenant General Joseph W. Stilwell, the US commander of the China Burma India Theater and chief-of-staff to Generalissimo Chiang Kai-shek, to authorise the immediate movement of Major General Su Li-jen’s Chinese 38th Division of Lieutenant General Chan Chen’s Chinese 66th Army from the Sittang river valley into the Yenangyaung area of the Irrawaddy river valley.
On 16 April, almost 7,000 British soldiers, together with 500 prisoners and civilians, were encircled by an equal number of men of Lieutenant General Shozo Sakurai’s Japanese 33rd Division of Lieutenant General Shojiro Iida’s 15th Army at Yenangyaung and its oilfield. The 33rd Division was able to advance between Major General D. T. Cowan’s Indan 17th Division at Taungdwingyi and the 1st Burma Division to the south of Yenangyaung. Fearing that his Burma Corps might become trapped, Slim called on the Chinese 38th Division for help. Sun Li-jen sought authority to take his entire division to the rescue of the 1st Burma Division, but Lieutenant General Lo Cho-ying, executive officer of Lin Wei, refused and on 17 April, therefore, Sun instead led his 113th Regiment of a mere 1,121 men, of which only 800 were combat personnel, towared Yenangyaung. Because the Chinese had neither artillery nor tanks, Slim assigned Anstice’s 7th Armoured Brigade to the Chinese force. The brigade comprised two battalions of M3 Stuart light tanks and one battery of 25-pdr gun/howitzers.
For the next three days the Chinese attacked to the south. The temperatures reached as high as 46° C (114° F) and a pall of smoke from the demolished oil wells and refineries hung over the battlefield.
Meanwhile, the 1st Burma Division fought its way to and across the Pin Chaung river, where it met the relief column on 19 April. On the next day, the Chinese force attacked to the south toward Yenaungyaung and Pin Chaung. The attack caused the Japanese heavy casualties, but the Allied forces were too weak to hold the oilfields and had to retreat to the north.
For the British, deprived of supplies and reinforcements by the loss of Rangoon and now of fuel by the loss at Yenangyaung, the operational question was no longer whether or not to retreat, but to where to retreat.