Although we typically date the beginning of the Second World War as 1 September 1939, when Germany attacked Poland, and Britain and France declared war on Germany in response, the fighting in Asia had started much earlier. The Empire of Japan had attacked China - itself in the middle of a bloody civil war - in 1931, seizing the province of Manchuria. In 1937 Japan resumed hostilities with an invasion of central China, seizing the capital of Nanjing, and perpetrating one of the worst atrocities of the war, killing almost 200,000 civilians.
Bitter fighting between the Japanese and Chinese would continue for the next eight years - but in 1941 Japan attacked the American naval base at Pearl Harbour, as well as British forces across the far-east - in Hong Kong, Singapore and Malaysia. This would prove to be a fatal mistake, with the Japanese unable to wage war on three fronts: the Chinese in the East, the British Empire in their south, and the Americans sailing from the east, across the Pacific Ocean.

Initially the Japanese surprise attacks worked well. The American Pacific fleet lost several battleships and cruisers (though importantly, none of their aircraft carriers), and the British lost two battleships in Malaysia, and suffered humiliating defeats with the successive falls of Hong Kong and Singapore.
In 1942 the Japanese launched their invasion of British ruled Burma (now Myanmar), leading to one of the most gruelling and protracted campaigns of the entire Second World War, brutal jungle warfare that led to the deaths of over 400,000 soldiers - and as many as 1,000,000 Burmese civilians.
The Fourteenth Army that resisted the Japanese invasion, led by General William Slim, became one of the most diverse and effective fighting forces in history. Their victories at Imphal and Kohima in 1944 were turning points, halting the Japanese advance into India and pushing them back through Burma. This saved India from the Japanese advance, and kept the supply lines between the Western Allies and the Chinese forces north of the Himalayas intact.
