 Complete the following phrase:  World War I broke out when Austria-Hungary invaded Serbia on 28 July 1914. Russia entered the war on 1 August 1914. On 22 August 1914, Sheydemans 2nd Army Corps was transferred to the 1st Army under General Paul von Rennenkampf. After General Samsonovs 2nd Army was almost completed destroyed during the Russian defeat in the Battle of Tannenberg in late August and an ashamed Samsonov committed suicide, Sheydeman took command of the 2nd Army on 5 September 1914. In September, Sheydemans 2nd Army participated in the 