The Battle of Changsha of 1944 (also known as the Battle of Hengyang or Campaign of Changsha-Hengyang; ) was an invasion of the Chinese province of Hunan by Japanese troops near the end of the Second Sino-Japanese War. As such, it encompasses three separate conflicts: an invasion of the city of Changsha and two invasions of Hengyang.
The Japanese military transferred the bulk of their troops from the Japanese homeland and Manchuria as part of Operation "Ichi-Go" or "Tairiku Datsu Sakusen" which roughly translates as 'Operation to Break through the Continent'. This was an attempt to establish a land and rail corridor from the Japanese occupied territories of Manchuria, Northern and Central China and Korea and those in South East Asia.
Japanese objectives
thumb|Chinese soldiers taking positions during the battle in May 1944
Changsha is the capital city of Hunan province and an important junction of two railroads in southern China: the tri-province railroad of Hunan-Guizhou-Guangxi and the one from Canton to Wuhan. Hengyang is also on the tri-province railroad and very close to the Canton-Wuhan Railroad. Furthermore, Lake Dongting and the cities of Changsha, Hengyang, and Lingling, are connected by the Xiang River. It was imperative for both sides to control the suburban areas of Changsha and Hengyang.
The tactical objective of the Japanese China Expeditionary Army was to secure the railroad of Hunan-Guizhou-Guangxi and the southern area of China. The United States 14th Air Force of United States Army Air Forces also stationed their fighters and bombers at several air bases along the three-province railroad: Hengyang, Lingling, Guilin, Liuzhou, and Nanning. From there, the American Flying Tigers led by Brigadier General Claire Lee Chennault, had inflicted heavy damage on Japanese troops both in China and Formosa and could launch air strikes against the home islands of Japan.
After several ineffective air strikes by the Imperial Japanese Army Air Service, the Japanese decided to use ground forces to deny Allied air power these air bases. By a direct order from Shunroku Hata, Commander-in-Chief of the Japanese China Expeditionary Army, the Japanese 11th Army stationed at Wuhan was given the mission to attack Changsha and advance southwest via the tri-province railroad. It was later to join forces with the Japanese 23rd Army of the Japanese Sixth Area Army from Canton.
General Isamu Yokoyama (橫山勇), the two-star general of the Japanese 11th Army, headed five divisions reinforced by four more divisions and three independent brigades. Shunroku Hata decided to stay at Wuhan from 25 May 1944 until the end of the second phase of Operation Ichi-Go.
Battle of Hengyang
Two Japanese military detachments moved on to besiege Hengyang, but the NRA's understrength Tenth Corps under the command of Fang Xianjue repelled their advance twice. The predicament in Hengyang helped hasten the crumbling of Hideki Tojo's cabinet. In conjunction with the loss of Saipan on 9 July 1944, Tojo and his cabinet handed in their resignation on 18 July 1944.
In August 1944, Japanese troops led by three two-star generals again attacked Hengyang with air support. Chinese troops resisted fiercely aided by local knowledge and constructing effective barricades up to four meters high. The Chinese defenses were intelligently constructed and used crossfire zones to maximize firepower. This caused the Japanese 68th and 116th Divisions to lose morale and it began preparations for retreat. Morale rose, however, when the Japanese 58th Division broke into the northwest perimeter of the city, defended by the Chinese Third Division and the attack resumed. Reinforcements from five Corps: the 37th, 62nd, 74th, 79th, and 100th, attempted many times to reach Hengyang, but were blocked by four Japanese divisions: the 27th, 34th, 40th, and 64th. The 68th and 116th Divisions lost their combat strength and were reassigned to garrison duties. Thus, the Chinese troops to the north were able to expand their influence despite the loss of Hengyang city. The Japanese 11th Army received 100,000 additional soldiers to supplement the combat and non-combat losses in the Changsha-Hengyang campaign.
On the side of the Chinese National Revolutionary Army, Xue's Ninth Military Front in this campaign lost two effective corps loyal to Chiang Kai-Shek: the 4th and the 10th corps. This rendered "Tiger Xue" a toothless tiger until the end of the Second Sino-Japanese War.
Sequentially, the Japanese 11th Army moved toward Lingling, seizing it on 4 September 1944, and controlled Guilin on 10 November 1944.