Zhilinsky also served from 22 February 1911 to 4 March 1914 as Chief of the General Staff of the Imperial Russian Army. At the beginning of World War I, he assumed command of the Northwestern Front. The Northwestern Front included the 1st Army and 2nd Army under the command of General Paul von Rennenkampff and General Alexander Samsonov. After the unsuccessful East Prussian Campaign and the losses at the Battle of Tannenberg and the First Battle of the Masurian Lakes, he was relieved of command despite attempts to blame Rennenkampff for the fiasco. Zhilinsky was sent as a military representative to France from 1915–1916 and was recalled to Russia in the autumn of 1916. On 19 September 1917, he was ordered to retire.