The Japanese 21st Army was formed on September 19, 1938 under the Imperial General Headquarters.
It was transferred to the control of the China Expeditionary Army on September 23, 1939 and assigned the primary role in the Canton Operation (the invasion of Guangdong Province in southern China), together with the Imperial Japanese Navy’s 5th Fleet.
By October 21, the provincial capital of Guangzhou was under Japanese control.
The IJA 5th Division continued to advance up the Pearl River and by November 5 had taken the city of Foshan.
By the end of November, the entire province was under Japanese control.