Soviet annexation of the western Ukrainian territories On the basis of a secret clause of the Molotov – Ribbentrop Pact between Nazi Germany and the Soviet Union ( USSR ) , the Soviet Union invaded Poland on September 17 , 1939 , capturing the eastern regions of Poland ( Kresy ) , with Galicia and Volhynia , facing little Polish opposition and occupying the principal city of the ethnic region Western Ukraine , Lviv ( ) , on September 22 of that year . On June 26 , 1940 Moscow issued an ultimatum to the kingdom of Romania demanding ceding of the territories in the region of northern Bukovina ( where Ukrainians were the ethnic majority ) , which was occupied by the Red Army on August 2 of that year . As a result of these annexations the territory of the Ukrainian Soviet Socialist Republic gained of territory and increased its population by over 7 million people . Annexation of Polish territory . On September 17 , 1939 the Red Army entered Polish territory , acting on the basis of a secret clause of the Molotov – Ribbentrop Pact between the Soviet Union and Nazi Germany . Soviet Union would later deny the existence of this secret protocol , claiming that it was never allied with Nazi Germany , and acted independently to " protect " the Ukrainian and Belorusan minorities in the disintegrating Polish state . Composed of mostly ethnic Ukrainian Soviet troops under the command of Marshal Semyon Timoshenko , the Soviet forces occupied Western Ukraine within 12 days , capturing the regions of Galicia and Volhynia with little Polish opposition and occupying the principal city , Lviv , on September 22 of that year . Due to Polish government ' s discrimination against the Ukrainian minority during the interbellum , these troops were sometimes greeted with genuine joy by Ukrainian villagers , In other cases , support demonstrations were staged by pro - Soviet militia . Not all Ukrainians , however , trusted the Soviet regime responsible for the Ukrainian Famine of 1932 – 1933 . In practice , the poor generally welcomed the Soviets , while the elites tended to join the opposition , despite supporting the unification of Ukraine . Immediately after entering Poland ' s territory , the Soviet army helped to set up " provisional administrations " in the cities and " peasant committees " in the villages in order to organize one - list elections to the People ' s Assembly of Western Ukraine . The elections were designed to give the annexation an appearance of validity , but were far from free or fair . The voters had a choice of only one candidate , often a local communist or someone sent to western Ukraine from Sоviet Ukraine for each position of deputy ; the communist party commissars then provided the assembly with resolutions that would push through nationalization of banks and heavy industry and transfers of land to peasant communities . Elections took place on October 22 , 1939 ; the official numbers reported participation of 93 percent of the electorate , 91 percent of whom supported the appointed candidates . Based on these results , the People ' s Assembly of Western Ukraine , headed by Kyryl Studynsky ( a prominent academic and figure in the Christian Social Movement ) , consisted of 1 , 484 deputies . They met in Lviv on October 26 – 28 , where they were addressed by Nikita Khrushchev and other representatives of the Ukrainian Soviet Socialist Republic . The assembly voted unanimously to thank Stalin for liberation and sent a delegation headed by Studynsky to Moscow to ask for formal inclusion of the territories into the Ukrainian SSR . The Supreme Soviet voted to do so on November 1 , 1939 and on November 15 a law was passed making Western Ukraine a part of the Ukrainian SSR . Annexation of Romanian territory . On June 26 , 1940 , Soviet People ' s Commissar Vyacheslav Molotov presented an ultimatum note to Gheorghe Davidescu , Romanian ambassador to Moscow , in which the Soviet Union demanded the evacuation of the Romanian military and administration from Bessarabia and from the northern part of Bukovina within 24 hours , The Soviet government demanded the northern part of Bukovina as a " " minor reparation for the great loss inflicted to the Soviet Union and Bessarabia ' s population by 22 years of Romanian domination of Bessarabia " " , and because its " " [ . . . ] fate is linked mainly with the Soviet Ukraine by the community of its historical fate , and by the community of language and ethnic composition " " . Northern Bukovina has had some historical connections with Galicia , which was annexed by the Soviet Union in 1939 , in the sense that both were part of Austria - Hungary from the second part of the 18th century until 1918 . Also , unlike Bessarabia , Northern Bukovina had a Ukrainian majority . Romania promptly agreed to withdraw from the territories , to avoid a full scale military conflict . Majority of the territories were turned into the Moldavian SSR , a constituent republic of the USSR . Soviet policies in the annexed territories . Government and administration . The lands annexed by the Soviet Union were administratively reorganized into six oblast s similar to those in the rest of the Soviet Union ( Drohobych Oblast , Lviv Oblast , Rivne Oblast , Stanislav ( later known as Ivano - Frankivsk ) Oblast , Tarnopil Oblast and Volyn Oblast ) . The civilian administration in those regions annexed from Poland was organized by December 1939 and was drawn mostly from newcomers from eastern Ukraine and Russia ; only 20 % of government employees were from the local population . It was falsely assumed by many Ukrainians that a disproportionate number of people working for the Soviet administration came from within the Jewish community . The reason for this belief was that most of the previous Polish administrators were deported , and the local Ukrainian intelligentsia who could have taken their place were generally deemed to be too nationalistic for such work by the Soviets . In reality , most positions were staffed by ethnic Ukrainians from the Soviet Union . Nevertheless , in the eyes of many Ukrainians the Jews came to be associated with Soviet rule , which contributed to rising anti - Jewish sentiments . The Polish language was eliminated from public life , and Ukrainian became the language of the government and the courts . All Polish institutions were abolished , and all Polish officials , civil servants , and police were deported to Siberia or Central Asia . Ukrainian organizations not controlled by the Soviets were limited or abolished . Hundreds of credit unions and cooperatives that had served the Ukrainian people between the wars were shut down . All local Ukrainian political parties were abolished , and between 20 , 000 to 30 , 000 Ukrainian activists , fled to German - occupied territory ; most of those who did not escape were arrested . For example , Dr . Dmytro Levitsky , former head of the moderate Ukrainian political party Ukrainian National Democratic Alliance ( UNDO ) that had dominated Ukrainian political life between the world wars , and chief of the Ukrainian delegation in the pre - war Polish parliament , was arrested alongside many of his colleagues , deported to Moscow , and never heard from again . The elimination of the individuals , organizations and parties that represented moderate or liberal political tendencies left the extremist Organization of Ukrainian Nationalists , which operated in the underground , as the only political party with a significant organizational presence left in western Ukraine . Education and healthcare . Due to the sensitive location of western Ukraine along the border with German - held territory , the Soviet administration made attempts , initially , to gain the loyalty and respect of the Ukrainian population . Healthcare , especially in the villages , was improved dramatically . Between the two world wars Poland had drastically reduced the number of Ukrainian - language schools while Romania had eliminated them completely . These were now reopened and , although the Russian language became a mandatory foreign - language course , the schools were taught in Ukrainian . Ukrainian was reintroduced in the University of Lviv ( where the Polish government had banished it during the interwar years ) , which became thoroughly Ukrainized and renamed after Ukrainian writer Ivan Franko . The Soviet authorities established a branch of the Ukrainian Academy of Sciences in Lviv , and some leading non - Communist Ukrainian scholars were invited to staff these institutions . University students from Eastern Ukraine were brought to Lviv and western Ukrainian students , professors , and other cultural figures were sent on Soviet - funded trips to Kiev . An unintended result of such exchanges was that the Galician youth were disagreeably surprised by the material poverty and widespread use of the Russian language in Soviet Ukraine , while the incoming students to western Ukraine became exposed to and sometimes came to adopt western Ukrainian nationalism . In contrast to the dramatic expansion of educational opportunities within the Soviet system , non - Soviet controlled educational institutions such as the popular Prosvita society reading rooms , the Shevchenko Scientific Society , libraries and community theaters , and the Russophile Stauropegion Institute were closed or abolished . Land reform . In the annexed territories , over 50 percent of the land had belonged to Polish or Romanian landlords while approximately 75 % of the Ukrainian peasants owned less than two hectares of land per household . Starting in 1939 lands not owned by the peasants were seized and slightly less than half of them were distributed to landless peasants free of charge ; the rest were given to new collective farms . The Soviet authorities then began taking land from the peasants themselves and turning it over to collective farms , which affected 13 % of western Ukrainian farmland by 1941 . This caused the peasants to turn against the Soviet regime . Religious persecution . At the time of the Soviet annexation of western Ukraine the Ukrainian Greek Catholic Church had approximately 2 , 190 parishes , three theological seminaries , 29 monasteries , 120 convents and 3 . 5 million faithful . Its leader , Andrey Sheptytsky , was seen as a " father figure " by most Western Ukrainians . The married Western Ukrainian Clergy and their children formed a caste that had a high degree of influence within Ukrainian society . Using his moral influence , Sheptytsky persuaded all but approximately 100 of the Ukrainian Catholic priests in western Ukrainian to stay with their flock in western Ukraine rather than flee from the Soviet regime . Due to its immense popularity , as well as that of Sheptytsky , among the western Ukrainian people , the Soviet Union did not attempt to abolish the Ukrainian Greek Catholic Church nor persecute its leader at that time . Instead , it sought to limit the Church ' s influence by banishing its presence from schools , preventing it from printing ( 20 Ukrainian Catholic journals or newspapers were shut down ) , confiscating lands from which it derived income , closing monasteries and seminaries , levying high taxes , and introducing anti - religious propaganda into schools and the media . The Soviets also attempted to undermine the Church from within . A prominent Lviv priest and close confidante of Andrey Sheptytsky , Havriil Kostelnyk , who had been the principle critic of the Vatican ' s Latinization policies and spokesperson for the " Easternizing " trend within the Ukrainian Catholic Church , was asked to organize a " National " Greek Catholic Church , with Soviet support , that would be independent of the Vatican and which would split the faithful in western Ukraine . At this time , he refused to cooperate , even after the autumn of 1940 when the Soviets arrested his youngest son in order to blackmail him . ( After Sheptytksy ' s death , however , Kostelnyk would play a significant role in the destruction of the Ukrainian Greek Catholic Church ) . Arrests , though not of a mass nature , were used in order to terrify the religious leaders . For example , in June 1940 the superior of the Studite convent in Lviv , Olena Viter , was imprisoned and tortured in order to " confess " that Sheptytsky was a member of the Organization of Ukrainian Nationalists and that she was supplying him with weapons . She refused to do so . By the summer of 1941 , in Western Ukraine 11 or 12 Greek Catholic priests were murdered or missing , and fifty - three were imprisoned or deported . Despite the various restrictions , the Ukrainian Greek Catholic Church was left as the only remaining independent Ukrainian institution that operated openly in Ukrainian territory . Church attendance soared , and contemporary accounts described churches never having been as full as they became under Soviet rule , with long lines forming in front of confessional booths . The western Ukrainian people attempted to protect their Church from Soviet restrictions . Peasants , even among the poorest ones , were reluctant to accept land taken from the Church and offered to them , and as late as May 1940 some villages had not yet expropriated church lands , while others distributed much of it to priests ' families . Priests made homeless were taken in by parishioners . Children , who no longer learned religion in school , obtained religious instruction privately . The Ukrainian Autocephalous Orthodox Church in Volhynia faced similar restrictions to those of the Ukrainian Greek Catholic Church ; moreover it underwent pressure to subordinate itself to the Moscow Patriarch . Many Orthodox priests fled the Soviet regime , resulting in a large number of newly consecrated priests who were not necessarily fit for their duties , weakening and demoralizing the Church somewhat . The Orthodox hierarchs in western Ukraine were left alone , however . Deportations and Demographic changes . Initially , the Soviet authorities deported primarily political figures as well as all Polish officials , civil servants , police , and Polish citizens who had fled from the Germans . The exact number of Poles deported to Siberia or Central Asia between 1939 and 1941 remains unknown , and has been estimated at from under 500 , 000 to over 1 , 500 , 000 ; about 350 , 000 of whom died . In Bukovina , in accordance with the agreement between the Soviet Union and Germany , most of the region ' s large German minority was repatriated . The German consul also evacuated many local Ukrainian leaders and Orthodox priests , many of whom subsequently joined the Melnyk branch of the Organization of Ukrainian Nationalists abroad . Tens of thousands of German - speaking people from Volhynia were also moved to German - controlled territory . In April 1940 the Soviet authorities in the annexed territories began to extend their repressive measures towards the general Ukrainian population . This coincided with the removal of Soviet troops of ethnic Ukrainian origin , who had become too friendly with local Ukrainians , and their replacement by soldiers from Central Asia . The Soviet authorities began arresting and deporting anyone suspected of disloyalty to the Soviet regime . In villages , people were denounced by their neighbors , some of whom were Communist sympathizers while others were opportunists . Deportations became indiscriminate , and people and their families were deported for " crimes " such as having relatives or visiting abroad , or visiting friends while the friends were arrested . Because many of those making denunciations were perceived to be Jews , anti - Jewish sentiments among the Ukrainian population increased . Ultimately , between 1939 and the beginning of World War II approximately 500 , 000 Ukrainians would be deported to Siberia and central Asia . In addition to the loss of much of the native population , western Ukraine experienced an influx of other settlers . The population of Lviv increased from 318 , 000 to 450 , 000 during the Soviet administration , largely due to the influx of Polish refugees fleeing German territory and Soviet officials and their families . The latter group was estimated to number 100 , 000 people in Lviv . In Stanislaviv ( now Ivano - Frankivsk ) the population grew by 40 , 000 , 1 , 000 of whom were estimated to have been NKVD officers . In addition , 100 , 000s of Jews fleeing Nazi terror in German - occupied Poland arrived in the territories newly annexed by the USSR . Aftermath . On June 22 , 1941 Operation Barbarossa began , and western Ukraine was captured within weeks . Prior to retreating , the Soviet authorities , unwilling to evacuate prisoners , chose to kill all inmates whether or not they had committed major or minor crimes and whether or not they were held for political reasons . Estimates of the number of people killed vary from 15 , 000 to 40 , 000 . Due to the brutality of the Soviet administration , many Ukrainians initially welcomed the German invasion . On June 30 , 1941 , Ukrainian nationalist commandos under German command captured Lviv which had been evacuated by Soviet forces and declared an independent state allied with Nazi Germany . This movement was quashed by the Germans , who split up western Ukraine . Northern Bukovina was returned to Germany ' s ally , Romania . Galicia , which had once been part of Austria , was made part of the General Government together with occupied Poland , while Volhynia was split off and attached to the Reichskommissariat Ukraine . All of these regions would be captured and reintegrated into Soviet Ukraine in 1944 . Importance for the Ukrainian statehood . The annexation of 1939 was an important event in the history of Ukraine , because it brought within one republic most of Ukrainian ethnic territories and unified previously separated Ukrainian populations . Thus the unified during this time Ukrainian SSR eventually achieved independence in 1991 after the fall of the Soviet Union .