The Battle of Hong Kong (also called the Defence of Hong Kong) took place on Hong Kong Island and the adjacent mainland territories (Kowloon and the New Territories) in the British Crown Colony of Hong Kong. It occurred from December 8 to December 25, 1941, as part of the Pacific Theater of World War II. Japanese forces invaded, and after 18 days of fighting, the British-led garrison surrendered. The battle marked the beginning of nearly four years of Japanese occupation.