Japanese Occupation Era (1940s):
The Japanese occupation of Hong Kong began after the Governor of Hong Kong, Sir Mark Young surrendered the territory of Hong Kong to Japan on 25 December, 1941 after 18 days of fierce fighting by British and Canadian defenders against overwhelming Japanese Imperial forces. The occupation ultimately lasted for three years and eight months, leading many survivors to call the occupation as simply "Three Years and Eight Months".
The British, Canadians, Indians and the Hong Kong Volunteer Defence Forces resisted the Japanese invasion commanded by Sakai Takashi which started on 8 December 1941, eight hours after the attack on Pearl Harbor. Japanese achieved air superiority on the first day of battle and the defensive forces were outnumbered. The British and the Indians retreated from the Gin Drinker's Line and consequently from Kowloon under heavy aerial bombardment and artillery barrage. Fierce fighting continued on Hong Kong Island; the only reservoir was lost. Canadian Winnipeg Grenadiers fought at the crucial Wong Nai Chong Gap that secured the passage between downtown and the secluded southern parts of the island.
On 25 December 1941 - which has gone down in history as Black Christmas to local people - British colonial officials headed by the Governor of Hong Kong, Mark Aitchison Young, surrendered in person at the Japanese headquarters on the third floor of the Peninsula Hotel. Isogai Rensuke became the first Japanese governor of Hong Kong.
During the Japanese occupation, hyper-inflation and food rationing became the norm of daily lives. It became unlawful to own Hong Kong Dollars, which were replaced by the Japanese Military Yen, a currency without reserves issued by the Imperial Japanese Army administration. Some estimate that as many as 10,000 women were raped in the first few days after Hong Kong's capture and large number of suspected dissidents were executed. Philip Snow, a prominent historian of the period, said that the Japanese cut rations for civilians to conserve food for soldiers, usually to starvation levels and deported many to famine- and disease-ridden areas of the mainland. Most of the repatriated actually had come to Hong Kong just a few years earlier to flee the terror of the Second Sino-Japanese War in mainland China.
By the end of the war in 1945 by liberation in Hong Kong by joint British & Chinese troops against the Japanese during the Second Battle of Hong Kong, the population of Hong Kong shrunk to 600,000, less than half of the pre-war population of 1.6 million. The communist takeover of mainland China in 1949 led to another population boom in Hong Kong. Thousands of refugees emigrated from mainland China to Hong Kong, and made it an important entrepĂ´t until the United Nations ordered a trade embargo on mainland China due to the Korean War. More refugees came during the Great Leap Forward.