Who won the Battle of the Niemen?
Poland won. Between 20 and roughly 28 September 1920 the Polish 2nd and 4th Armies under Józef Piłsudski broke the new Soviet front of Mikhail Tukhachevsky on the Niemen. A northern hook through Druskieniki outflanked Grodno, the Red Army fell back, and about 40,000 Soviet soldiers were taken prisoner. An armistice followed on 12 October.1
In September 1920, a month after the Battle of Warsaw, the Polish and Soviet armies met again along the river Niemen around Grodno. The Polish victory there, which the Institute of National Remembrance calls the final blow of the war, broke the Red Army's ability to attack and opened the way to an armistice. The Lithuanian encyclopedia VLE ranks it as the second most important battle of the Polish-Soviet War, after Warsaw.2
Background: a second chance for Tukhachevsky
After his defeat at Warsaw in August 1920, Mikhail Tukhachevsky rebuilt his Western Front along the Niemen and brought in troops and supplies from deep inside Russia. In the south the Polish cavalry had just beaten Budyonny's cavalry army at Komarów. Tukhachevsky did not see the war as lost. Michał Szukała quotes him as writing that the lost operation made him want to attack again; he kept the confidence of Moscow and prepared a new offensive, still aimed, Szukała writes, at Warsaw. The Polish command saw the danger too: on 26 August the chief of the General Staff, General Tadeusz Rozwadowski, judged that about half of the Soviet forces had been destroyed but that the rest, once refilled, could threaten Poland again before the end of the year, as Janusz Odziemkowski shows from the staff papers.3
Piłsudski's plan
On 10 September, at Brest, Józef Piłsudski set out the situation to the commanders of his 2nd and 4th Armies and called for another quick victory. The operation was planned at his own headquarters and he led it in person, while the General Staff ran the southern front, Odziemkowski notes. Under the order of 19 September, as the AAN portal summarizes it, the 2nd Army of General Edward Rydz-Śmigły was to take Grodno with its center while its left wing marched through the forests south of Sejny, in a strip then held by Lithuanian troops, to envelop the city from the north; the 4th Army of General Leonard Skierski was to attack frontally toward Wołkowysk and cross the Szczara. The plan was a gamble: with both armies worn out, as the IPN notes, much depended on who struck first.4
The armies
Numbers depend on who is counted. Michał Szukała gives Tukhachevsky more than 70,000 men for his planned offensive and puts the strength of his divisions at the start of September at almost 114,000, while VLE counts about 130,000 Polish soldiers, 195,000 in the final phase, against about 145,000 Soviet. VLE adds that the soldiers of both sides were poorly armed, poorly trained and tired.5
Grodno: the frontal battle
The Polish attack began on 20 September, when the 2nd Army struck at Grodno. The fighting was fierce and, as the IPN puts it, victory did not come at once. The Great Soviet Encyclopedia, written from the other side, dates the renewed Polish offensive in Belarus to 19 September and says only that it made no significant progress.6
The northern hook and the Lithuanian dimension
The decisive move was made on Lithuanian-held ground. On 22 September Polish troops attacked the Lithuanian positions around Sejny, and units of the 2nd Army crossed the Niemen at Druskieniki, today's Druskininkai: on 22 September according to VLE's entry on the battle, which also names a crossing at Hoża, and on 23 September according to its entry on the Sejny operation, while the AAN portal puts the march on Druskieniki at 23 to 25 September. VLE puts the losses of the Lithuanian 2nd Infantry Division in the fighting of 22 and 23 September at 34 killed, 103 wounded and more than 2,000 taken prisoner, with ten guns lost. The AAN portal, by contrast, records only that the 4th Cavalry Brigade beat the Lithuanians at Podlipki and took Druskieniki. Lithuania and Poland were not formally at war, and the two accounts reflect very different views of the same days.7
Why was the Battle of the Niemen important?
It finished what Warsaw had begun. By outflanking Grodno through Druskieniki, the Poles wrecked a planned Soviet offensive and drove the Red Army back to the east. In the words of the IPN, the Bolshevik threat was finally removed. Jarosław Centek adds that the Poles were exhausted too, so both sides agreed to a truce; the peace talks had moved to Riga on 21 September, while the battle was still going on.8
The turning point: Grodno falls, the retreat begins
With Polish troops behind the Niemen, the Soviet line began to give way. According to the AAN portal, Polish units began crossing the Niemen in the city at midnight on the night of 25 to 26 September under heavy fire and took Grodno in night fighting; the Polish History Museum's chronology dates its capture to 25 September. Further south the 4th Army took Wołkowysk on 23 September, was pushed out by a counterattack the next morning and held the town again by the evening of the 25th, according to the same portal. Threatened with encirclement, Tukhachevsky ordered a general retreat on 26 September, Szukała writes.9
Lida: the hardest fight
Lida lay across the Soviet line of retreat. The AAN portal records that on 27 September the 1st Lithuanian-Belarusian Division closed the road at Lebioda, while the 1st Legions Infantry Division and Lieutenant Colonel Adam Nieniewski's cavalry group took Lida and blocked the retreating Soviets. After these very hard fights in the woods of Krwawy Bór near Lebioda and at Lida, the portal says, the Soviet 3rd Army lost its operational capability. The IPN likewise credits the 1st Legions Infantry Division with halting a large part of the retreating Soviet troops.10
How many were captured and killed?
Losses were never fully counted, because Soviet units broke up as they fled. VLE puts the prisoners taken in the battle at about 40,000, with 140 captured guns according to its entry on the war; Szukała gives the same totals for prisoners and guns in Polish hands by 12 October. According to the AAN portal, the defeat at Warsaw had already shrunk some Soviet divisions to a few hundred bayonets. Polish losses were heavy, with several hundred dead and wounded at Krwawy Bór and at Lida alone, according to the Archives of Modern Records (AAN); no reliable overall total is available.11
The Soviet side
For the Red Army the Niemen was a second disaster within six weeks. Centek writes that Tukhachevsky had to retreat and that his front could not hold back the Polish pursuit. Soviet historiography told it differently: the Great Soviet Encyclopedia's article on the war does not name the battle at all, says the Polish offensive of September made no significant progress, and presents the peace as forced on a Poland exhausted by the war.12
The Lithuanian side
For Lithuania the battle mattered above all because of Vilnius. In its peace treaty with Soviet Russia of 12 July 1920 Lithuania had been promised the city, in return, VLE writes, for a neutrality that covered the Red Army's right flank. Talks with Poland led to the Suwałki agreement of 7 October, which drew a demarcation line from East Prussia to Bastuny and left Vilnius on the Lithuanian side; VLE stresses that it did not settle the question of Vilnius. Two days later, on 9 October, General Lucjan Żeligowski's division, officially in mutiny, took the city. The Lithuanian historian Gintautas Ereminas writes that Żeligowski acted on Piłsudski's verbal order and that the seizure broke the Suwałki agreement.13
Aftermath: armistice and the Peace of Riga
Polish forces pursued the Soviets eastward and took Minsk. On 12 October an armistice was signed in Riga, and fighting stopped on 18 October. The Peace of Riga, signed on 18 March 1921, ended the war. Its text in the Polish Journal of Laws names Poland on one side and Russia and Ukraine on the other, with the Russian delegation signing also for Soviet Belarus, and the historian Mariusz Wołos stresses that Soviet Ukraine was a signatory in its own right. The Internet Encyclopedia of Ukraine notes that the delegations of the Ukrainian National Republic, Poland's ally in the war, and of the Western Ukrainian National Republic were not admitted to the talks.14
How it is remembered
In Poland the Niemen has long stood in the shadow of Warsaw and the Miracle on the Vistula, even though, as the AAN portal argues, it was the victory that finally decided the war and deserves an equal place in memory. Szukała counts it among the greatest Polish victories and calls it almost forgotten, and the Polish Senate's resolution of 2019 naming 2020 the Year of the Battle of Warsaw mentions it only as the end of the pursuit after Warsaw. Lithuanian reference works link it above all to the Polish seizure of Vilnius that followed. Even its dates are counted differently: Centek gives 20 to 26 September, other Polish sources 20 to 28, and VLE's entry on the battle 21 to 30 September.15
The battlefield today
The ground is now divided by borders that did not exist in 1920. Grodno, known today as Hrodna, and Lida lie in Belarus, while Druskininkai, where the Poles crossed the Niemen, is a spa town in southern Lithuania. The river that both armies tried to hold now runs past three countries, each of which remembers that September differently.
