The 'Battle of Vigan' was one of the initial movements in the Japanese 'M' (ii) invasion of Luzon in the Philippine islands group (10 December 1941).

The landing was one of a series of advance assaults made by Imperial Japanese forces as first step in their invasion of the Philippine islands group, and in this particular instance was designed to obtain control of local airstrips, which could be used as forward bases by fighter aircraft for operations farther to the south. The landing at Vigan was preceded two days earlier by the landing on Batan island, and essentially concurrent assaults were made on Camiguan island and Aparri, with more landings made at Legaspi on Luzon island, Davao on Mindanao island and on Jolo island over the next few days.

Vigan is the capital of the Ilocos Sur province in the north-west of Luzon island, about 220 miles (355 km) to the north of Manila on the coastal Route 3. It is bordered on the east by the Cordillera mountains, which separate it from the Cagayan river valley. The town is about 3 miles (3.8 km) from the coast, and served by the port of Pandan on the mouth of the Abra river. In 1941, the Vigan area was in theory defended by Major General Jonathan M. Wainwright’s North Luzon Force. However, with only a few men and a large territory to cover, Wainwright could spare only one partially trained and equipped Philippine army formation, the 11^th Division, commanded by Colonel William E. Brougher, for all of northern Luzon. A reserve formation, the 11^th Division had started 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 a serious shortage of equipment, including almost all of its artillery and transport.

On the Japanese side, Lieutenant General Masaharu Homma’s 14^th Army had organised a detachment from Lieutenant General Yuitsu Tsuchihashi’s 48^th Division, namely the 2^nd Regiment under the command of Colonel Kanno, as the core of the assault force. This numbered approximately 2,000 men of the 3/2^nd Regiment and half of the 1/2^nd Regiment. The invasion force was transported and supported by Rear Admiral Shoji Nishimura’s 2^nd Surprise Attack Force, which comprised the the light cruiser Naka, the destroyers Murasame, Yudachi, Harusame, Samidare, Asagumo, Minegumo and Natsugumo, six minesweepers, nine anti-submarine craft and six transport vessels. This naval force assembled at Mako in the Japanese-occupied Pescadores islands group, between Formosa and the Chinese mainland, and arrived at Vigan before dawn on 10 December. The landing was covered by aircraft of the Imperial Japanese army air force’s 24^th and 50^th Fighter Regiments operating from the new Japanese airfield at Batan island captured on the previous day.

At the same time as the landing operation of the 'Tanaka' Detachment at Aparri, the 'Kanno' Detachment disembarked at Vigan and found no opposition from US or Filipino forces; however. Reports of the landing reached the headquarters of General Douglas MacArthur’s US Army Forces in the Far East in Manila after a reconnaissance flight by a Curtiss P-40 warplane, and Major General Lewis H. Brereton’s Far East Air Force responded with the despatch of five Boeing B-17 Flying Fortress four-engined heavy bombers escorted by P-40 and Seversky P-35 single-engined fighters of the 34^th Pursuit Squadron.

The initial wave of the 'Kanno' Detachment had secured the town Vigan by 10.30 but, as at Aparri, the Japanese landing operation was hampered by heavy seas and strong winds. The US aircraft attacked the Japanese maritime force with bombs and strafing attacks, and one of the Japanese transports, the Oigawa Maru, was forced to beach to prevent sinking. A second transport, the Takao Maru, was also beached after a subsequent attack, and the minesweeper W-10 was sunk. The Japanese also suffered casualties on the destroyer Murasame and the light cruiser Naka, which lost three men killed, and 30 men in the transport Hawaii Maru were wounded, despite air cover by 18 fighters of the 24^th Fighter Regiment.

As a result of continuing bad weather, the 2^nd Surprise Attack Force was shifted 4 miles (6.4 km) to the south, where it was finally able to land the remainder of the 'Kanno' Detachment on 11 December. A small detachment was quickly sent to the north to capture Laoag, capital of Ilocos Norte province, 50 miles 980 km) away, along with its airfield.

With the US-led forces retreating, Homma decided to leave only a small garrison at Vigan, and to move the bulk of his combat forces to the south to assist the Japanese landing force at Lingayen Gulf.

By 13.00 on 20 December the 'Tanaka' Detachment from Aparri and the 'Kanno' Detachment had joined as a single regiment, and marched out of Vigan to the south along coastal Route 3. Repairing destroyed bridges along the way, the Japanese had reached the town of Bacnotan by the evening of 21 December. Bacnotan was defended by elements of the 11^th Division, but the Japanese made a flanking movement to the east and forced part of the defenders back, while cutting off reinforcements from the mountains to the east. The Japanese reached San Fernando, La Union, on the morning of 22 December, only a few hours after the main elements of the 14^th Army began the Japanese invasion of Lingayen Gulf, just to the south.

In retrospect, the advance landings by the Japanese in the northern part of Luzon, including that at Vigan, 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 the support of further operations.