1st Division (Imperial Japanese Army)

The 1st Division (第1師団) was an infantry division in the Imperial Japanese Army. Its call sign was the Jade Division (玉兵団).

History
The 1st Division was formed in Tokyo in January 1871 as the Tokyo Garrison (東京鎮台), one of six regional commands created in the fledgling Imperial Japanese Army. The Tokyo Garrison had responsibility for the eastern region of Honshū (Kantō region), centered on the Tokyo metropolitan area. The six regional commands were transformed into divisions under the army reorganization of 14 May 1888, based on recommendations by the Prussian military advisor Jakob Meckel to the Japanese government.

As one of the oldest Divisions in the Imperial Japanese Army, the 1st Division saw combat in the First Sino-Japanese War and the Russo-Japanese War and the Nonomhan Incident.

The February 26 Incident was an attempted coup d'état staged by elements of the 1st Division in Tokyo in 1936.

From 1937, the 1st Division was stationed in Manchukuo, where it came under the command of the Kwantung Army, and where it was assigned to guard the northern border of Manchukuo against the Soviet Union.

During later stages of the Pacific War the 1st Division was reassigned to the Philippines, and initially based in Manila where it formed the core of General Tomoyuki Yamashita's 14th Area Army. Ordered to oppose the re-occupation of Leyte by the American and Filipino forces, the 1st Division landed at Ormoc City on the west coast of Leyte on 1 November 1944. Their orders were to move up Leyte Highway Number 2 to Carigara and to secure the northern half of the island. However, American and Filipino forces had already seized Carigara, and American air strikes had deprived the Japanese 1st Division of its supply chain and reinforcements. Unable to reach Carigara, the Japanese fortified hilltops and ridges along the highway, and defended these areas against the US and Philippine Commonwealth military offensive from 7 November 1944 though 12 December 1944, in fierce combat, including combat in the middle of a typhoon. By the time Leyte was secured by American and Filipino forces, of the 11,000 Japanese soldiers sent to the Battle of Leyte, only 800 remained alive. Following the Battle of Leyte, the 1st Division ceased to exist as an operational unit.

Some of the more noteworthy commanders in the history of 1st Division include: Miyoshi Shigomi, Oku Yasukata, Kawamura Kageaki HIH Prince Fushimi Sadanaru, HIH Prince Kanin Kotohito, Ichinohe Hyoe, Yoshinori Shirakawa, and Jinzaburo Mazaki.

Organization
The original order of battle of the 1st Division was as a Square Division.

1st Division
 * 1st Infantry Brigade
 * 1st Infantry Regiment
 * 49th Infantry Regiment
 * 2nd Infantry Brigade
 * 3rd Infantry Regiment
 * 57th Infantry Regiment
 * 1st Field Artillery Regiment
 * 1st Cavalry Regiment
 * 1st Engineer Regiment
 * 1st Transport Regiment

When it was later reorganized as a Triangular Division, it had the following organization:

1st Division
 * 1st Infantry Brigade Group
 * 1st Infantry Regiment (Azabu)
 * 49th Infantry Regiment (Kofu)
 * 57th Infantry Regiment (Sakura)
 * 1st Mountain Artillery Regiment
 * 1st Recon Regiment
 * 1st Engineer Regiment
 * 1st Transport Regiment

Reference and further reading

 * Madej, W. Victor, Japanese Armed Forces Order of Battle, 1937-1945 [2 vols], Allentown, Pennsylvania: 1981
 * Morison, Samuel Eliot. History of United States Naval Operations in World War II. Vol. 13: The Liberation of the Philippines—Luzon, Mindanao, the Visayas, 1944-1945 University of Illinois Press (2002), ISBN 0-252-07064-X
 * Vego Milan N. Battle for Leyte, 1944 : Allied And Japanese Plans, Preparations, And Execution. Naval Institute Press, 2006. ISBN 1-55750-885-2