Oahu

From Turtledove

Oahu is the third largest and most populous of the Hawaiian Islands.

[edit] Oahu in Days of Infamy

Oahu was the first island invaded by the Japanese Army on December 8, 1941. After subduing it, and the American forces defending it, the remaining islands fell quickly to Japanese rule. Naturally, when the Americans reinvaded in 1943, they landed at Oahu. Fierce fighting took place across the island as Japan refused to yield. When Japanese forces were subdued, the United States began the process of rebuilding.