As part of the final defenses of the
Philippines against invasion and re-occupation by
Allied forces in the closing stages of
World War II,
Imperial General Headquarters issued orders for the strategic island of
Luzon to be divided into three defense sectors for defense in depth under the overall command of the
Japanese Fourteenth Area Army. From 17 December 1944, Lieutenant General
Shizuo Yokoyama and his "Shimbu Group", an independent detachment, were made wholly responsible for the defense of southern Luzon, from
Manila southwards. The Shimbu Group was officially re-designated the Japanese 41st Army on 6 March 1945. Yokoyama commanded Japanese forces defending Manila against the
U.S. Sixth and
Eighth Armies. Following the
Battle of Manila, the Shimbu Group faced the 6th Army in the
Battle of Wawa Dam and Battle of Ipo Dam, and lost decisively. Yokohama withdrew his surviving forces into the mountains of southern Luzon for a protracted
guerrilla campaign, continuing to harass Allied forces until the
surrender of Japan. By the time Yokoyama signed the instrument of surrender in Montalban, Luzon on September 8, 1945, his army had been reduced to just 6500 men. ==List of Commanders==