The Russian Empire had a particular interest in Kwantung, being one of the few areas in the region with the potential to develop ice-free ports for its expansion in the Far East, and Qing authorities withdrew the lease from the Japanese following the Triple Intervention, only weeks after it had been granted.

It was headquartered in Port Arthur (known as Ryojun in Japanese) and was administered as a department by the Kwantung Government-general, and the governor-general served concurrently as its commander.

[1] In the highly politicized Imperial Japanese Army of the 1920s and 1930s, the Kwantung Army was a stronghold of the radical "Imperial Way Faction" (Kōdōha), and many of its senior leaders overtly advocated political change in Japan through the violent overthrow of the civilian government to bring about a Shōwa Restoration, with a reorganization of society and the economy along state fascist lines.

Conspirators within the junior officer corps of the Kwantung Army plotted and carried out the assassination of Manchurian warlord Zhang Zuolin in the Huanggutun Incident of 1928.

Presented with the fait accompli, Imperial General Headquarters had little choice but to follow up on the actions of the Kwantung Army with reinforcements in the subsequent Pacification of Manchukuo.

In 1932, the Kwantung Army was the main force responsible for the foundation of Manchukuo, the puppet state of Japan located in Northeast China and Inner Mongolia.

When full-scale war broke out in the Marco Polo Bridge Incident in July 1937, its forces participated in the Battle of Beiping-Tianjin and Operation Chahar.

However, by the late 1930s, the Kwantung Army's vaunted reputation was severely challenged during the Soviet–Japanese border conflicts that Japan had fought against the Soviet Union in northern Manchukuo since 1932.

After the "Nomonhan incident", the Kwantung Army was purged of its more insubordinate elements, as well as proponents of the Hokushin-ron ("Northward Advance") doctrine who urged that Japan concentrate its expansionist efforts on Siberia rather southward towards China and Southeast Asia.

[9] At these locations, the Kwantung Army was also responsible for some of the most infamous Japanese war crimes, including the operation of several human experimentation programs using live Chinese, American, and Russian[12] civilians, and POWs, directed by Dr. Shirō Ishii.

Arrested by the American occupation authorities, Ishii and the 20,000 members of Unit 731 received immunity from prosecution of war crimes before the Tokyo tribunal of 1948, in exchange for germ warfare data based on human experimentation.

Among those sentenced to death were former generals Seishirō Itagaki, Iwane Matsui, Kenji Doihara, Hideki Tōjō, and Akira Mutō.