During the 1938 Battle of Gubeikou in the Sino-Japanese War, Japanese soldiers carried the bodies of their fallen comrades. The Japanese forces crossed the Great Wall and invaded, gaining complete control over Jehol Province under the Tanggu Agreement.

 　During the Battle of Gubeikou in 1938, the Sino-Japanese War, Japanese soldiers carried the bodies of their fallen comrades. The Japanese forces crossed the Great Wall and invaded, gaining complete control over Jehol Province under the Tanggu Agreement. This allowed the Kwantung Army in Manchuria and the China Garrison Army in the Beijin-Tianjin area to easily coordinate, setting Japan's sights on full-scale invasion of North China.

　To conquer the North China Plain, the heartland of China, Gubeikou became the most crucial strategic point for the Japanese Army. During the Battle of Gubeikou, the Japanese deployed tanks and won after fierce fighting. In March 1938, Chinese Nationalist forces were killed by machine gun fire from Japanese tanks.

　Having completed the occupation of Manchuria and the three northeastern provinces, Japan's next target was Jehol Province, situated between North China. On February 23, 1938, following a decision by the Japanese government, the Jehol Invasion Operation commenced. Subsequently, in mid-March, the Japanese forces repelled Chinese troops at Shanhaiguan, the Yanbian Pass of the Great Wall. They occupied territory stretching approximately 450 km up to Gubeikou (Old North Gate). By May, Japanese forces crossed the Great Wall again, invading the Inner China region of North China, the area inside the Great Wall. They advanced into North China, approaching within 50 km of Beijing. 

　　The Chinese side was forced to request a ceasefire. Soon, the occupation expanded to include Jehol Province, with the Great Wall line as the boundary. This effectively meant China accepted inclusion into Manchukuo, a puppet state of the Japanese military and a Japanese occupied colony. The Japanese military invaded across China's Great Wall and, based on the Tanggu Agreement, brought Rehe Province (热河省) completely under its control. The Japanese Kwantung Army in Manchuria and the Japanese China Garrison Army in Beiping and Tianjin could now easily coordinate with each other, allowing Japan to fully pursue its invasion of China's North China region.