World War II: Japan begins the Aleutian Islands Campaign by bombing Unalaska Island.

The Empire of Japan, also known as the Japanese Empire or Imperial Japan, was the period of Japanese history spanning 79 years, starting with the Meiji Restoration on 3 January 1868, and ending with ratification of the Constitution of Japan on 3 May 1947. From August 1910 to September 1945, it included the Japanese archipelago, the Kurils, Karafuto, Korea, and Taiwan. The South Seas Mandate and concessions such as the Kwantung Leased Territory were de jure not internal parts of the empire but dependent territories. In the closing stages of World War II, with Japan defeated alongside the rest of the Axis powers, the formalized surrender was issued on 2 September 1945, in compliance with the Potsdam Declaration of the Allies, and the empire's territory subsequently shrunk to cover only the Japanese archipelago, excluding Okinawa until the handover in 1972.