Batan Island: History
=== Japanese invasion ===
The Japanese invasion of the Philippines began with the invasion of Batan Island by a 490-man naval combat unit and a number of air corps troops aboard two transports escorted by one destroyer and four torpedo boats. This was the first landing on American territory, which transpired on the same day as the attack on Pearl Harbor.
Japanese forces quickly secured the existing small airfield outside Basco without resistance and began expansion work immediately as a forward base of operations against Luzon. Work was discontinued only a few days later as the success of the Japanese bombing of Clark Field rendered an airfield in Basco redundant. On 10 December 1941, the naval combat force was redeployed.