The 'Battle of Aparri' was one of the initial stages of the Japanese 'M' (ii) seizure of Luzon island in the Philippine islands group (10 December 1941).
The purpose of the undertaking was to obtain control of small airstrips in the north of Luzon, which could then be used as forward bases by fighters of the Imperial Japanese army air force for the support of larger operations farther to the south. The first of these small-scale invasions was on Batan island on 8 December 1941, and the following two landings in northern Luzon took place at Vigan and Aparri two days later.
Before World War II, Aparri was an important port city, with a population of 26,500. However, although located at the mouth of the Cagayan river, it is isolated from the rest of Luzon by mountain ranges to the east, west and south. Manila and the central plains of Luzon were connected to Aparri by Route 5 through the narrow Balete Pass to the south, or by a long coastal route. The Cagayan river valley was not regarded by the US-led US and Filipino force as a likely invasion route.
The area of Aparri was in theory defended by Major General Jonathan M. Wainwright’s North Luzon Force. With only a small strength and a large territory to cover, Wainwright could spare only one partially trained and equipped Philippine army formation, the 11th Division, commanded by Colonel William E. Brougher, for the defence of all northern Luzon. A reserve formatio, the 11th Division had begun to mobilise only in September and was at a mere two-thirds of its authorised strength of 1,500 men per regiment. It also suffered from major shortages of equipment, including almost all of its artillery and transport. This division maintained only one battalion in the entire Cagayan river valley, with only one company actually at Aparri. On the Japanese side, Lieutenant General Masaharu Homma’s 14th Army had organised a detachment from Lieutenant General Yuitsu Tsuchihashi’s 48th Division, namely the 2nd Regiment under the command of Colonel Toru Tanaka, for the assault. This 'Tanaka' Detachment numbered about 2,000 men of the 2/2nd Regiment, half of the 1/2nd Regiment and the regimental headquarters. The landing force was transported and supported by Rear Admiral Kenzaburo Hara’s 1st Surprise Attack Force,which comprised the light cruiser Natori, the destroyers Fumizuki, Nagatsuki, Satsuki, Minazuki, Harukaze and Hatakaze, three minesweepers, six anti-submarine craft and six transport vessels. The force assembled at Mako in the Japanese-occupied Pescadores islands group, between Formosa and mainland China, and reached Aparri, toward the western end of Luzon’s northern coast, before dawn on 10 December. The landing operation was covered by aircraft of the Imperial Japanese army air force’s 24th and 50th Fighter Regiments operating from the airfield om Batan island captured on the previous day.
The landing operation at Aparri faced no opposition from US or Filipino forces, but after two companies had landed, rough seas and high winds forced a shift in location to Gonzaga, some 20 miles (32 km) to the east. Reports of the landing soon reached the headquarters of General Douglas MacArthur’s US Army Force in the Far East in Manila, where it was correctly assumed that the objective was to seize airfields from which fighters could deploy for operations farther to the south. However, Wainwright considered the landing at Aparri to be a feint to divide his already weak defences, and decided not to offer resistance aside from destroying bridges on the route from Balete Pass.
As the Japanese were unloading at Gonzaga, two Boeing B-17 Flying Fortress four-engined heavy bombers from Clark Field attacked the transport vessels. One of the aircraft was piloted by Captain Colin Kelly, who reported that he had attacked and severely damaged a Japanese battleship before he was shot down: the pilot was posthumously portrayed extensively in Allied propaganda material as the first war hero for flying his damaged aeroplane into the funnel of the battleship Haruna as the first kamikaze; but there were no Japanese battleships in the area, and the only losses suffered by the Japanese in this attack was slight damage to the light cruiser Natori and the loss of the minesweeper W-19,which was holed and had to be beached.
The 'Tanaka' Detachment reported the capture of Aparri airfield by 13.00, and the airfield at Camalaniugan by the evening of the same day. Construction troops began work immediately on expanding the runways and establishing depot facilities, and the 36 Nakajima Ki-27 'Nate' single-engined fighters of the 50th Sentai (fighter regiment) were operational at Aparri by the following day.
By 12 December, the 'Tanaka' Detachment had also secured Tuguegarao airfield, 50 miles (80 km) to the south. With the US and Filipino forces on the retreat, Homma at this juncture decided to leave only a small garrison at Aparri, and to move the bulk of his combat forces to south to assist the major invasion force at Lingayen Gulf.
In retrospect, the advance landings by the Japanese in the northern part of Luzon, including that at Aparri, accomplished little of strategic or tactical value. The airfields seized were small, and with the rapid advance of the Japanese into central Luzon, were soon unnecessary for further operations.