Germany–Japan relations Kaiserliche Marine in and around Chinese waters. Japan, eager to reduce the presence of European colonial powers in South-East Asia, especially on China's coast, sent Germany an ultimatum on 14 August 1914, which was left unanswered. Japan then formally declared war on the German Empire on 23 August 1914 thereby entering the First World War as an ally of Britain, France and the Russian Empire to seize the German-held Caroline, Marshall, and Mariana Islands in the Pacific. The only major battle that took place between Japan and Germany was the siege of the German-controlled Chinese port of Tsingtao in Kiautschou
War crimes in occupied Poland during World War II at Chełmno according to postwar verdict by West Germany, although up to 340,000 victims were estimated by the Polish Main Commission for Investigation of German Crimes in Poland (GKBZNwP), a predecessor of the Institute of National Remembrance. Following the Wannsee Conference of 1942, as part of highly secretive Operation Reinhard in occupied Poland, the German government built three regular killing centres with stationary gas chambers. It was the most deadly phase of the Final Solution, based on implementing semi-industrial means of killing and incinerating people. The new facilities included Treblinka extermination camp (set up in July 1942), Bełżec (March 1942),