It was active from November 18, 1941 to April 9, 1942, whereupon it surrendered when Bataan fell.

It was organized and trained in Zambales Province of Northern Luzon.

Col. Pastor C. Martelino (PA), a 1920 U.S. Military Academy graduate, was his chief of staff.

[1][2] At the opening of hostilities, 8 December 1941, the 31st Division formed a part of BGen.

Jonathan M. Wainwright's North Luzon Force of the Philippine Army (later renamed I Philippine Corps), alongside the 11th and 21st Divisions, and the 26th Cavalry Regiment.