Japanese Eighteenth Area Army

The Japanese Eighteenth Area Army (第18方面軍) was a field army of the Imperial Japanese Army during World War II.

History
The 18th Area Army was originally formed on January 4, 1943 as the Siam Garrison Command (泰国駐屯軍司令官). It was renamed the Japanese Thirty-ninth Army on December 14, 1944 and became the 18th Area Army on July 7, 1945, shortly before the end of the Pacific War.

The 18th Area Army was under the control of the Southern Expeditionary Army Group as a military reserve and garrison force, ostensibly to help defend the Empire of Japan's nominal ally, the Empire of Siam against possible invasion by the Allies, but in more practical terms, it was present to ensure that Siam remained an ally to Japan. It was headquartered in Bangkok.

The 18th Area Army was demobilized in Bangkok at the surrender of Japan on August 15, 1945 without having seen combat.