A precedent for trying those accused of war crimes had been set at the end of World War I in the Leipzig War Crimes Trials held in May to July 1921 before the Reichsgericht (German Supreme Court) in Leipzig, although these had been on a very limited scale and largely regarded as ineffectual. At the beginning of 1940, the Polish government-in-exile asked the British and French governments to condemn the German invasion of their country. The British initially declined to do so; however, in April 1940, a joint British-French-Polish declaration was issued. Relatively bland because of Anglo-French reservations, it proclaimed the trio's "desire to make a formal and public protest to the conscience of the world against the action of the German government whom they must hold responsible for these crimes which cannot remain unpunished."