Slovakia during World War II Slovakia during World War II was a member of the Axis Powers . The Slovak State ( also the first state of the Slovaks ) was founded with help of Nazi Germany . After the Slovak - Hungarian War Hungary annexed a great part of the country . In 1940 , under pressure from Germany , Slovakia joined the Axis . Since 1939 , Slovak forces participated in the Axis invasion of Poland and the invasion of the Soviet Union . Slovak State foundation . The desire for autonomy was one of the great issues of Slovaks in Czechoslovakia . Josef Tiso and nationalists of the Slovak People ' s Party pushed for Slovak independence and aligned themselves with the National Socialist Party in Germany . Hitler promised Tiso that he would support him if he separated Slovakia from Czechoslovakia . On March 14 , 1939 Slovakia declared independence , calling itself the Slovak Republic . German troops soon occupied Bohemia and Moravia . War with Hungary . On November 2 , 1938 , the First Vienna Award transferred the territories of southern Slovakia and southern Ruthenia to Hungary . Hungary was granted an area of 11 , 927 km ² with a population of 869 , 299 , of which , according to the 1941 Census , 86 . 5 % were ethnic Hungarians . Hitler even promised transfer all of Slovakia to Hungary in exchange for military support from Budapest in the war soon to be unleashed against the Soviet Union , but the Hungarians were reluctant to engage in conflict . Instead , they agreed to a territorial revision along ethnic separation lines . Hungary recognized the Slovak Republic led by Jozef Tiso . On March 23 , 1939 a border war broke out between Slovakia and Hungary . Although Slovakia had signed a " Protection Treaty " with Nazi Germany , in direct violation of that treaty , Germany refused to help Slovakia . Ending 11 days later , on April 4 , 1939 the Slovak - Hungarian War ( also called the " Little War " ) resulted in the Hungarian occupation of a narrow strip of the common border that had previously been Slovakia ' s . Invasion of Poland . In September 1939 , National Socialist Germany invaded Poland . Slovak troops fought alongside German troops and Hitler ' s armies occupied much of eastern Europe . As the war went on , Slovaks began to turn on Germans in greater numbers and Slovak troops rebelled . On AUgust 29 , 1944 rebels began the Slovak National Uprising against the German - controlled Tiso government . Hitler ' s forces spent two months before crushing the rebellion . Soviet forces liberated Slovakia in May 1945 . Second World War . The Tripartite Pact , also the Three - Power Pact , Axis Pact , Three - way Pact or Tripartite Treaty was a pact signed in Berlin , Germany on September 27 , 1940 , which established the Axis Powers of World War II . On November 24 , 1940 , Slovakia signed on to the Tripartite Pact . After a few months , Hitler asked the newly formed Slovakian Republic to join in the military action against Poland . War in the East . Slovakia did not participate at the start of the invasion of the Soviet Union , which began on June 22 , 1941 . Hitler did not ask for help from Slovakia , however the Slovaks decided to send an expeditionary group . The Slovak Army group attached to the 17th German Army attacked the Soviet 12th . Along with the 17th Aramta German and Hungarian army , the group submitted the Slovak army deep into southern Russia . During the Battle of Uman ( 3 to 8 August 1941 ) , a mechanized body of the Carpathian Group formed double wings encircling the 6th and 12th Soviet units . During this struggle , 20 Soviet divisions were destroyed or have surrendered . Approximately 60 , 000 of the 95 , 000 Slovakian Jews were deproted and sent to death camps in Poland before 1942 . Then the Slovak government made a deal with Germany for the Jews to be " delivered " in exchange for needed workers for the Slovak National Socialist war economy . After Wannsee Conference , the Germans agreed with the Slovaks proposal and the two parties came to an agreement by which the Slovak Republic had to pay a fixed amount for each Jew deported a fixed amount and in return , Germany promised that Jews were not deported never to return to Slovakia . Slovak National Uprising . On the 29th August 1944 , the Slovak National Uprising broke out after German troops invaded Slovakia . The German occupation troops resumed the forwarding of the Final Solution by deporting Slovakian Jews to mass death camps in Germany and Poland . Slovakia soon became a theater of war . On September 19 the German command replaced the force that was responsible for combat troops that revolted , with general Hoff . By that time the Germans had 48 , 000 soldiers , and consisted of eight German divisions , including four of the Waffen - SS and a pro - National Socialist Slovak format . On October 1 rebel army was renamed the Czechoslovak Army in Slovakia one in order to symbolize the beginning of Czech - Slovak reunification that would be recognized by the allied forces . A major German counteroffensive began on October 17 to 18 when 35 , 000 German soldiers entered the country from Hungary , which were under German military occupation of 19 March 1944 . Stalin demanded that the advancement of the Second Ukrainian Front led by General Malinovsky be immediately diverted to Budapest . The advance of Soviet forces west of the screeching stopped in late October 1944 , because Stalin ' s interests have focused on Hungary , Austria and Poland before being interested in Slovakia or the Czech Republic . By the end of October , the Axis forces ( six German divisions and pro - National Socialist Slovak unit ) took back most of the territory from the insurgents and surrounded the battle groups . The fighting cost flights at least 10 , 000 casualties on both sides . The insurgents had to evacuate Banská Bystrica on October 27 just before the German takeover . SOE and OSS agents retreated to the mountains , with thousands of others fleeing the German advance . On October 28 , General Viest has sent a message to London , that the resistance is moving towards guerilla warfare . On October 30 , General President Hoffa and Tiso celebrated in Banská Bystrica , with medals for German soldiers for their part in suppressing the revolt . However , supporters of regular forces with remnants continued their efforts in the mountains . In retaliation , the Slovaks have executed several suspected rebelune and Jews avoided deportation by then , and destroyed 93 villages for suspected collaboration . A later estimated death toll was 5304 and the authorities have discovered 211 mass graves that resulted from these atrocities . Most execution took place in Kremnička and Nemecká . On 3 November the Germans captured Golian Bukovec Pohronský Vieste and they later interrogated and executed . SOE and OSS teams eventually joined and sent a message requesting immediate assistance . The Germans surrounded both groups from 25 December and they have captured . Some men were summarily executed . The Germans took the rest of the Mauthausen concentration camp , where they were tortured and executed . German victory only delayed the final fall of the pro - National Socialist . Six months later , the Red Army invaded the Axis forces in Slovakia . By December 1944 , Romanian and Soviet troops were killed German troops in southern Slovakia , the Battle of Budapest . On 19 January 1945 , the Red Army had Bardejov , Svidník , Prešov and Košice in eastern Slovakia . On March 3 to 5 took northwestern Slovakia . On 25 March came on April 4 , Banská Bystrica and marched in Bratislava . Although the main military objectives were not achieved due to improper timing of the uprising and the actions of Soviet partisans who discoordinate often undermined plans and objectives Slovak armed insurrection - if it occurred later , when preparations were complete as Slovakia could theoretically back the whole of the Allies and allowed the Red Army to move quickly through Slovakia ( although it is questionable whether the Soviet leadership would have preferred such an option , as this would be significantly empowered democratic forces in Slovakia ) - guerrilla forces required imported from Germany that could have otherwise strengthened Wehrmacht on the eastern front lines against the advancing fronts of Ukraine to the north and south of Slovakia . However , much of Slovakia was devastated by German bombing rebellion and counter - offensive and occupation . ( As in German ) . Aftermath . After signing Peace Treaty of Paris , Slovakia lost its independence being reunification with the Czech Republic . Hungarian and Czechoslovak authorities have forced an exchange of population .