What is 1st Army (Russian Empire)?
The '''Russian First Army''' was a [[World War I]] [[Russia]]n [[field army]] that fought on the [[Eastern Front (World War I)|Eastern Front]] for two years. == August 1914 == It was commanded by [[General officer|General]] [[Paul Rennenkampf]] when Russia [[Invasion|invaded]] [[East]] [[Prussia]] at the outbreak of war in 1914.<ref name=Grant64>R G Grant; et al., ''World War I: The Definitive Visual History'' (New York: DK Publishing, 2014), p. 64</ref> They were accompanied by the [[Second Army (Russian Empire)|Second Army]] commanded by General [[Alexander Samsonov]].<ref name=Grant64/> The plan was to trap the German army in a [[Pincer movement]] between the two armies.<ref name=Tucker979>''Encyclopedia Of World War I: A Political, Social, And Military History''. eds. Spencer C. Tucker; Priscilla Mary Roberts (Oxford: Abc-clio, 2005), p. 979</ref> On 17 August the First Army engaged the [[Germany|Germans]] at [[Nesterov|Stallupönen]]. They fought the Germans again on 20 August at [[Gusev, Kaliningrad Oblast|Gumbinnen]] and defeated them.<ref name=Tucker979/> Rennenkampf thought the Germans could be finished off by Samsonov's Second Army and did not move quickly enough to help them. In late August 1914 the German and Russian second army met at [[Battle of Tannenberg (1914)|Tannenberg]]. The Second Army was [[:en:wikt:encircle|encircled]] and suffered complete destruction. == September 1914 == Let by General [[Paul von Hindenburg]] the Germans turned [[north]] to attack the [[Russia]]n First army at [[First Battle of the Masurian Lakes]] in September 1914. The Russians fought hard but were driven back to the Russian border.<ref name=Tucker608>''World War One: Student Encyclopedia'', eds. Spencer Tucker, Priscilla Mary Roberts (Santa Barbara, CA: ABC-CLIO, 2006), p. 608</ref> Rennenkampf kept his troops in good order as they retreated.<ref name=Tucker608/> They set up defensive lines on the Russian border. == November 1914 == After another defeat near [[Silesia]] on November 11, Rennenkampf was dismissed.