Japan controlled the Kwangtung Leasehold, an area in Manchuria, containing Port Arthur and Darien (Manchuria). Today, the former Manchuria region is known as Dong Bei and the former Port Arthur as Dalian.
Originally, Japan took control in the area after the First Sino-Japanese War, but returned it to China, which then leased it to Russia. The Russo-Japanese War, however, let Japan reoccupy it, and then obtain a 99-year lease in 1915. The South Manchurian Railroad Line, owned by a Japanese corporation, terminated in the Leasehold; the railroad provided cover for Japanese intelligence and covert action throughout Manchuria.
The Kwangtung Army was the Japanese military force that secured the Leasehold, and eventually used it as a staging area to move into China.
- David Bergamini (1971), Japan's Imperial Conspiracy, Morrow, p. 1091