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 pulled his Western Front back behind the Niemen, Szczara and Świsłocz rivers, with Grodno anchoring its northern end. In the south the Polish cavalry had just beaten Budyonny's cavalry army at Komarów. Tukhachevsky did not see the war as lost. According to the PAP account he told Lenin that Warsaw had not decided it, and he prepared a new offensive toward Białystok and Brest, rebuilding the 3rd, 15th and 16th Armies.3
Piłsudski's plan
On 10 September, at his headquarters in the fortress of Brest, Józef Piłsudski presented a plan to his commanders. The 2nd Army of General Edward Rydz-Śmigły and the 4th Army of General Leonard Skierski would pin the Soviets frontally at Grodno and Wołkowysk. The real blow would come from the north: a group of the 2nd Army would march through the strip of land around Sejny and Druskieniki, then held by Lithuanian troops, cross the Niemen and strike the Soviet rear toward Lida. The plan was a gamble. According to Szukała it made no allowance for a Soviet counteroffensive, and with both armies worn out, as the IPN notes, much depended on who struck first.4
The armies
Numbers depend on who is counted. The PAP account gives the two Polish armies about 67,000 combat troops, with a further reserve of some 30,000 stationed deep inside the country, and Tukhachevsky about 73,000 men for his planned offensive. Michał Szukała puts the strength of Tukhachevsky's 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. Both armies were exhausted after a summer of marching and fighting.5
Grodno: the frontal battle
The Polish attack began on 20 September, when the 2nd Army struck at Grodno. Soviet resistance was stubborn: according to Szukała, villages around Grodno changed hands several times. Once Tukhachevsky moved reserves toward Grodno the fighting grew heavier, above all at Brzostowica, a battle the Twoja Historia lexicon dates to 20 to 24 September. Further south the 4th Army took Wołkowysk on 23 September, but a Soviet counterattack the next morning pushed it back. The British liaison officer Major Mockett reported that the Polish attack had forestalled a Soviet offensive in this sector by about 24 hours.6
The northern hook and the Lithuanian dimension
The decisive move was made on Lithuanian-held ground. On 22 September Polish troops broke weak Lithuanian resistance at Sejny, and on 22 and 23 September units of the 2nd Army seized crossings over the Niemen at Druskieniki, today's Druskininkai; VLE also names a crossing at Hoża. VLE records that the Lithuanian units defending southern Suwałki region suffered significant losses in these clashes. Major Mockett, by contrast, wrote that both sides had orders not to fire on each other, though the Lithuanians did not always obey theirs, and that as far as he could tell the passage through Lithuanian territory went without incident. Lithuanian troops found on the Polish side, he added, surrendered with little or no fighting, and about 2,500 Lithuanians were prisoners in Polish hands. 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 and cutting the railways behind Tukhachevsky's armies, the Poles wrecked a planned Soviet offensive, took about 40,000 prisoners and pushed the front far to the east. The Red Army could no longer attack, and both sides turned to the armistice talks in Riga.8
The turning point: Grodno falls, the retreat begins
With Polish troops behind the Niemen, the Soviet line began to give way. Mockett reported that Polish troops entered Grodno at about 9 p.m. on 25 September; Polish accounts place its capture in the night of 25 to 26 September. Threatened with encirclement, Tukhachevsky ordered a general retreat on 26 September. Some of the costliest fighting took place in the woods at Krwawy Bór near Lebioda.9
Lida: the hardest fight
Lida lay across the Soviet line of retreat, and according to Mockett the Soviet command ordered it held at all costs. Mockett, PAP and the Twoja Historia lexicon date the Polish entry into the town to 28 September, the AAN portal to 27 September. The 1st Legions Infantry Division then held Lida against retreating Soviet divisions that tried again and again to break through, in fighting that lasted into the morning of 29 September. Mockett called it probably the severest battle of the war, fought largely with the bayonet.10
How many were captured and killed?
Losses were never fully counted, because Soviet units broke up as they fled. At Lida, Mockett had counted 8,000 prisoners and 40 guns by 29 September and expected about 12,000. 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. Mockett described Communists posted with machine guns behind the ranks to keep the men facing the Poles, and heavy desertion, yet he also wrote that officers on the spot had "never seen troops fight better" than two Soviet divisions trapped at Lida. Tukhachevsky's armies escaped full encirclement, but lost much ground and their striking power. According to PAP, Lenin, Trotsky and Kamenev now gave up the idea of carrying revolution west through Poland.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, according to PAP's chronology, for letting Soviet troops pass through its territory. Talks with Poland led to the Suwałki agreement of 7 October, which confirmed a provisional demarcation line in the Suwałki region; 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 but acting with Piłsudski's approval, took the city. VLE treats this as a breach of the agreement.13
Aftermath: armistice and the Peace of Riga
Polish forces pursued the Soviets eastwards and took Minsk in mid October. 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; PAP's chronology lists Soviet Russia and Soviet Ukraine as the parties facing Poland. Michał Szukała counts the Niemen among the greatest Polish victories.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 it decided the war, as Tomasz Gąsowski notes; Szukała calls it almost forgotten. Lithuanian reference works link it above all to the Polish seizure of Vilnius that followed. Even its dates are counted differently: Polish sources mostly give 20 to 26 or 28 September, VLE 21 to 30 September, and PAP's account ends it on 3 October.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.16
