Reichswehr soldiers before the attack on Nikischacht, 1919
After the outbreak of riots in Upper Silesia on 20 August 1919, the Reich government sent troops to Upper Silesia, in order to suppress the rebellion of the Polish population. On the day of the outbreak of riots, the Polish government broke off the negotiations with the Reich Government on issues of territorial concessions. The negotiations were led by the governments of both states under the provisions of the Versailles Treaty, after the allies recognized Poland as an independent state, granted it with large parts of the Prussian provinces of Posen and West Prussia, and earmarked a referendum on the national belonging of other parts of West Prussia, Upper Silesia and Mazury.