
Whenthe Second World War in Europe began, the territory which now forms the country ofBelarus was divided between theSoviet Union (specifically theByelorussian Soviet Socialist Republic) and theSecond Polish Republic. The borders of Soviet Belarus were greatly expanded in theSoviet invasion of Poland of 1939. In 1941, the country wasoccupied byNazi Germany. Following the German military disastersat Stalingrad andKursk, the collaborationistBelarusian Central Council (BCC) was formed by the Germans in order to raise local support for their anti-Soviet operations. The BCC in turn formed the twenty-thousand strongBelarusian Home Defence (BKA), active from 23 February 1944 to 28 April 1945.[1] Assistance to collaborators was offered by the local Soviet administrative governments, and prewar public organizations including the former Soviet Belarusian Youth.[2] The country was soon retaken by the Red Army in 1944. Devastated by the war, Belarus lost significant populations and economic resources. Many battles occurred in Belarusian territory. Belarusians also participated in the advance towardsBerlin.

TheMolotov–Ribbentrop Non-Aggression Pact of August 1939 had established anon-aggression agreement betweenNazi Germany and theSoviet Union, and a secretprotocol described howFinland,Estonia,Latvia,Lithuania,Poland (Second Polish Republic) andRomania would be divided between them.
In theInvasion of Poland of 1939 the two powers invaded and partitioned Poland, and to return theUkrainian, Belarusian, andMoldavian territories in the North and North-Eastern regions ofRomania (NorthernBucovina andBessarabia).
The Polish defense was already broken, with their only hope being retreat and reorganisation in the south-eastern region (theRomanian Bridgehead), when on 17 September 1939, it was rendered obsolete overnight. The 800,000 strong Soviet UnionRed Army, divided into theBelarusian andUkrainianfronts, invaded theeastern regions of Poland that had not yet been involved in military operations, in violation of theSoviet-Polish Non-Aggression Pact. Sovietdiplomacy were protecting theUkrainian andBelarusianminorities inhabiting Poland in view of Polish imminent collapse.
Polish border defence forces (Korpus Ochrony Pogranicza) in the east (about 25 battalions) were unable to defend the border, and Edward Rydz-Śmigły further ordered them to fall back and not engage the Soviets. This, however, did not prevent some clashes and small battles, like thedefence of Grodno was defended by soldiers and local population. The Soviets murdered a number of Poles, includingprisoners-of-war like GeneralJózef Olszyna-Wilczyński.Ukrainians rose against the Poles, and communist partisans organised local revolts, e.g. inSkidel, robbing and murdering Poles. Those movements were quickly disciplined by theNKVD.
Prior to the Soviet partisans support from the East, the Polish military's fall-back plan had called for long-term defence against Germany in the southern-eastern part of Poland (near theRomanian border), while awaiting relief from aWestern Allies attack on Germany's western border. However, the Polish government decided that it was impossible to carry out the defence on Polish territories. It ordered all units to evacuate Poland and reorganize in France.
Meanwhile, Polish forces tried to move towards the Romanian bridgehead area, still actively resisting the German invasion.
From 17 September to 20 September, the Polish ArmiesKraków andLublin were crippled at theBattle of Tomaszów Lubelski, the second largest battle of the campaign.Oksywie garrison held until 19 September. Polish gained victory at thebattle of Szack, and the Red Army reached the line of riversNarew,Bug,Vistula andSan by September 28, in many cases meeting German units advancing from the other side. The last operational unit of the Polish Army, GeneralFranciszek Kleeberg'sSamodzielna Grupa Operacyjna "Polesie", capitulated after the 4-dayBattle of Kock nearLublin on 6 October, marking the end of the September Campaign.
Adolf Hitler had argued inMein Kampf of the necessity ofacquiring new territory for German settlement (Lebensraum) inEastern Europe. However, these plans were delayed through the period of thePhoney War, followed by the Nazi invasions ofNorway,France and Benelux,Denmark, and the failedBattle of Britain.
Polish citizens took an active part in the Soviet partisan movement in the occupied territory of the former USSR. 2,500 Polish citizens took part in the Soviet partisan movement in the territory of the Byelorussian SSR,[3] of which 703 were awarded with Soviet state awards[4] A further 2000 Polish citizens took part in the Soviet partisan movement on the territory of the USSR.[5]
At 04:45 on 22 June 1941, four million German soldiers, to be joined by Italian, Romanian and otherAxis troops over the following weeks, burst over the borders and stormed into the Soviet Union, including theByelorussian SSR. For a month the offensive was completely unstoppable north of the Pripiet marshes, as thePanzer forcesencircled hundreds of thousands of Soviet troops in huge pockets that were then reduced by slower-movinginfantry divisions while the panzers charged on, following theBlitzkriegdoctrine.
Army Group Centre comprised two Panzer groups (2nd and 3rd), which rolled east from either side ofBrest and affected a double encirclement atBelostok and west ofMinsk. They were followed by 2nd, 4th and 9th Armies. The combined Panzer force reached theBerezina river in just six days, 650 km (400 mi) from their start lines. The next objective was to cross theDnieper river, which was accomplished by 11 July. Following that, their next target wasSmolensk, which fell on 16 July, but theengagement in the Smolensk area blocked the German advance until mid-September, effectively disrupting theblitzkrieg.

With the capture of Smolensk and the advance to theLuga river, Army Groups Centre and North had completed their first major objective: to get across and hold the "land bridge" between the Dvina and Dnieper.
The German generals argued for an immediate drive towards Moscow, but Hitler overruled them, citing the importance of Ukrainian grain and heavy industry if under German possession, not to mention the massing of Soviet reserves in theGomel area between Army Group Centre's southern flanks and the bogged-down Army Group South to the south.
After a meeting held inOrsha between the head of theArmy General Staff,GeneralHalder, and the heads of threeArmy Groups and armies, it was decided to push forward toMoscow since it was better, as argued by head ofArmy Group Center,Field MarshalFedor von Bock, for them to try their luck on the battlefield rather than just sit and wait while their opponent gathered more strength.
Atrocities against the Jewish population in the conquered areas began almost immediately, with the dispatch ofEinsatzgruppen (task groups) to round up Jewish people and shoot them. Local gentiles were encouraged to carry out their ownpogroms.[citation needed] By the end of 1941, there were more than 50,000 troops devoted to rounding up and killing Jews.[citation needed] In three years of occupation, between one and two million Soviet Jews were killed.

In the summer of 1944 a balcony-shaped frontline had shaped following advances by the Red Army during late 1943. This invited an encirclement attack to cut off and destroy Army Group Centre. ForOperation Bagration, as it was to be called, the Red Army achieved a ratio of ten to one in tanks and seven to one inaircraft over the enemy. At the points of attack, the numerical and quality advantages of the Soviets were overwhelming. More than 2.5 million Soviet troops went into action against the German Army Group Centre, which could boast a strength of less than 800,000 men. The Germans crumbled, with the loss of almost 400,000 men who were either overrun or encircled.Minsk, the capital, was taken on 3 July 1944, trapping 100,000 Germans. Ten days later the Red Army reached the prewarPolish border. InWest Belarus, as the Red Army approached thePolish Home Army launched theOperation Tempest. Despite the war now passing out of Belarus, theSoviet Fronts name "Byelorussian" kept their name until the end of the war, and were to distinguish themselves in the battles in Poland and Germany in 1944 and 1945.
In the Soviet Unionthe end of World War II in Europe is considered to be 9 May, when the surrender took effectMoscow time. This date is celebrated as anational holiday,Victory Day, orДень Победы inBelarus,Russia and some other post-Soviet countries.
Национальные Добровольческие формирования в Вермахте и Ваффен-СС