Q: When and why did the Russo-Japanese War break out? A: It broke out on 8 February The Russians and Japanese had been jostling for some years for control over Korea and Manchuria, which they both regarded as strategically and economically important.
Japanese Soldiers on their way to fight the Russians; The Russo-Japanese War - 10 February 1904 - 5 September 1905) or the Manchurian Campaign - a conflict that grew out of the rival imperialist ambitions of the Russian Empire and the Empire of Japan over Manchuria and Korea. The major theatres of operations were Southern Manchuria, specifically the area around the Liaodong Peninsula and Mukden, and the seas around Korea, Japan, and the Yellow Sea.
As seen in the film PORT ARTHUR, At the Siege of Port Arthur in the Russo-Japanese War Japanese forces mobilized coastal defence guns in order to bombard the town. This tactic influenced the usage of heavy artillery in WWI