Bohdan Khmelnytsky Bohdan Zynoviy Mykhailovych Khmelnytsky ( ) or Bogdan Khmelnitsky ( ) , ( c . 1595 – 6 August 1657 ) , was the Hetman of the Zaporozhian Host of the Crown of the Kingdom of Poland in the Polish – Lithuanian Commonwealth ( now part of Ukraine ) . He led an uprising against the Commonwealth and its magnates ( 1648 – 1654 ) which resulted in the creation of a Cossack state . In 1654 , he concluded the Treaty of Pereyaslav with the Tsardom of Russia , which led to the eventual loss of independence to the Russian Empire . Biography . Early life . Although there is no definite proof of the date of his birth , it has been suggested by Ukrainian historian Mykhaylo Maksymovych that it is likely 27 December 1595 ( St . Theodore ' s day ) . As it was the custom in the Orthodox Church , he was baptized with one of his middle names — Theodor , translated into Ukrainian as Bohdan . The latest biography of Khmelnytsky by Smoliy and Stepankov , however , challenges the 27 December date and suggests that it is more likely he was born on 9 November ( feast day of St Zenoby , 30 October in Julian Calendar ) and was baptised on 11 November ( feast day of St . Theodore in the Catholic Church ) Khmelnytsky was probably born in the village of Subotiv , near Chyhyryn in Ukraine at the estate of his father Mykhailo Khmelnytsky . Even though his father , a courtier of Great Crown Hetman Stanisław Żółkiewski , was of noble birth himself and belonged to the Clan Massalski , Abdank or Syrokomla , there was and is still controversy as to whether Bohdan belonged to the szlachta ( Polish term for noblemen ) himself . Some sources state that in 1590 his father Mykhailo was appointed as a sotnyk for the Korsun - Chyhyryn starosta Jan Daniłowicz , who continued to colonize the new Ukrainian lands near the Dnieper river . According to the above mentioned - source , Mykhailo established Chyhyryn and later his own family estates of Subotiv ( 5 miles from Chyhyryn ) and Novoseltsi . This , however , didn ' t prevent Khmelnytsky from considering himself a noble and his father ' s status as a deputy Starosta ( elder ) of Chyhyryn helped him to be considered as such by others . Later on , however , during the Uprising he would stress his mother ' s Cossack roots and his father ' s exploits with the Cossacks of the Sich . There is also no concrete evidence in regard to Khmelnytsky ' s early education . Several historians believe he received his elementary schooling from a church clerk until he was sent to one of Kiev ' s Orthodox fraternity schools . He continued his education in Polish at a Jesuit college , possibly in Jarosław , but more likely in Lviv , in the school founded by hetman Żółkiewski . He completed his schooling by 1617 and acquired a broad knowledge of world history and learned Polish and Latin . Later he learned Turkish , Tatar and French . Unlike many of the other Jesuit students , he did not embrace Roman Catholicism but remained Greek Orthodox . Service with the Cossacks . Upon completion of his studies in 1617 , Bohdan entered into service with the Cossacks . As early as 1619 he was sent along with his father to Moldavia , as the Polish – Lithuanian Commonwealth entered into war with the Ottoman Empire . His first military engagement was a tragic one . During the battle of Cecora ( Ţuţora ) on 17 September 1620 , his father was killed , and young Khmelnytsky among many others , including future hetman Stanisław Koniecpolski , was captured by the Turks . He spent the next two years in captivity in Constantinople , as a prisoner of an Ottoman Kapudan Pasha ( presumably Parlak Mustafa Pasha ) . Other sources claim that he spent his slavery in Ottoman Navy on galley s as an oarsman where he picked up a knowledge of Turkic languages . While there is no concrete evidence as to how he returned to Ukraine , most historians believe he either escaped or his ransom was paid . Sources vary as to by whom — his mother , friends , the Polish king — but perhaps by Krzysztof Zbaraski , ambassador of the Rzeczpospolita to the Ottomans , who in 1622 paid 30 , 000 thaler s in ransom for all prisoners of war captured at the Battle of Cecora . Upon return to Subotiv , Khmelnytsky took over the running of his father ' s estate and became a registered Cossack in the Chyhyryn Regiment where he later became a pysar ( a historical officer title among cossacks ) . Since 1625 he participated in several sea raids together with Zaporozhian Cossacks onto Constantinople . In those raids he earned his title of a sotnyk ( a leader of a hundred ) . In the meantime , his widowed mother married again , to Belarusian noble Vasyl Stavetsky , and moved to his estate , leaving Bohdan in charge of Subotiv . In a year she had another son , Hryhoriy , who curiously enough later preferred to take his mother ' s name and was known as Hryhoriy Khmelnytsky . For a short time he also served as a koniuszy to hetman Mikołaj Potocki , but relatively quickly they parted their ways after a personal conflict . Bohdan Khmelnytsky later married Hanna Somkivna , a daughter of a rich Pereyaslavl Cossack and they settled in Subotiv . By the second half of the 1620s they already had three daughters : Stepanida , Olena , and Kateryna . His first son Tymish ( Tymofiy ) was born in 1632 , and another son Yuriy was born in 1640 . During this time Bohdan Khmelnytsky was running his estate and advanced in his service in the Regiment . He first became a sotnyk and later advanced to the rank of a regiment scribe . He certainly had significant negotiation skills and commanded respect of his fellow Cossacks as on 30 August 1637 he was included in a delegation to Warsaw to plead the Cossacks ' case before the Polish King Władysław IV . Serving in the army of a Polish magnate and great commander , hetman Stanisław Koniecpolski , he participated in a rather successful campaign as the Commonwealth army , part of which was Bohdan ' s regiment , scored a decisive victory over the Crimean Khanate in 1644 . During this time , as some archival documents show , he also had a meeting in Warsaw with the French ambassador Count De Bregie , during which he discussed the possibility of Cossack participation in war in France . Sources vary as to whether in April 1645 he traveled to France ( to Fontainebleau ) to discuss further details of Cossack service in France ; this claim is supported by Ukrainian historiography but disputed by Polish scholarship . In October 1644 around two thousand Polish infantry soldiers ( some scholars think they were Cossacks , but the French sources do not actually name them as such ) went to France by sea via Gdańsk and Calais , where they participated in the siege and capture of Dunkerque . The Czapliński Affair . In the meantime another trouble was brewing at home . Upon the death of magnate Stanisław Koniecpolski , an advocate of fair treatment of Cossacks , his successor Aleksander redrew the maps of his possessions and laid claim to Khmelnytsky ' s estate , which he claimed was his . In his attempt to find protection from the powerful magnate , Khmelnytsky wrote numerous appeals and letters to different representatives of the Polish crown — but to no avail . At the end of 1645 the Chyhyryn starosta Daniel Czapliński officially received authority from Koniecpolski to seize the Subotiv estate . In summer of 1646 Khmelnytsky , using his favorable standing at the Polish court , arranged an audience with King Władysław IV to plead his case . Władysław , who wanted Cossacks on his side in the wars he planned , gave him a royal charter , which protected his rights to the estate . However , such was the structure of the Commonwealth at that time , and the lawlessness of its eastern realms , that even the King was not able to avert the confrontation with the local magnates . In the beginning of 1647 Daniel Czapliński openly started to harass Khmelnytsky in an attempt to force him off the land . On two occasions Subotiv was raided : considerable property damage was done and Khmelnytsky ' s son Yuriy was badly beaten . Finally , in April 1647 , Czapliński succeeded in evicting Khmelnytsky from the land , causing Khmelnytsky to move with his large family to a relative ' s house in Chyhyryn . In May 1647 Khmelnytsky arranged a second audience with the King to plead his case , but found the King unwilling to go into an open confrontation with a powerful magnate . In addition to the loss of the estate , his first wife Hanna died , leaving him alone with the children . While he promptly remarried to Motrona , his second wife , he was still unsuccessful in all of his attempts to find justice in regard to his estate . During this time , he met several higher Polish officials to discuss the Cossacks ' issue of the war with the Tatars and used this occasion again to plead his case with Czapliński , still unsuccessfully . While Khmelnytsky found no support from the Polish officials , he found it in his Cossack friends and subordinates . The case of a Cossack being unfairly treated by the Poles found a lot of support not only in his Chyhyryn regiment , but also with others including the Sich . All through the autumn of 1647 Khmelnytsky traveled from one regiment to another , and had numerous consultations with Cossack leaders throughout Ukraine . His activity raised suspicion among the Polish authorities already used to Cossack revolts ; he was promptly arrested . Koniecpolski issued an order for his execution , but the Chyhyryn Cossack polkovnyk who held Khmelnytsky was persuaded to release him . Not willing to tempt fate any further , Khmelnytsky headed for the Zaporozhian Sich with a group of his supporters . The Uprising . While it might appear that the Czapliński Affair was the immediate cause of the Uprising , it was only an impetus that brought a successful and talented Cossack to the forefront of popular discontent among the people of what is now Ukraine . Religion , ethnicity , and economics factored into this discontent . While the Polish – Lithuanian Commonwealth remained a union of two nations : of Poland and Lithuania , a sizable population of Orthodox Ruthenians remained ignored . That left them oppressed by the Polish magnates and their wrath was directed at the Poles ' Jewish traders , who often ran their estates for them . The advent of the Counter - Reformation further worsened relations between the Orthodox and Catholic Churches . Many Orthodox Ukrainians saw the Union of Brest as a threat to their Orthodox faith , and coupled with the frequent abuse of the Orthodox clergy this added a religious dimension to the conflict . This could have been one of the many other frequent Cossack revolts that had been put down by the authorities , but the stature and skill of , and respect for , the seasoned 50 - year - old negotiator and warrior Khmelnytsky perhaps made all the difference . Initial successes . At the end of the year Khmelnytsky finally made his way to the south , to the estuary of the Dnieper river . On December 7 , 1648 his small ( 300 – 500 - man ) detachment , with the help of registered Cossacks who went to his side , disarmed the small Polish detachment guarding the area and took over the Zaporozhian Sich — much to the jubilation of many of the Cossacks . An attempt to retake the Sich by the Poles was decisively fought off as more registered Cossacks joined his forces . At the end of January 1649 a Cossack Rada was called and Khmelnytsky was unanimously elected a hetman . A feverish activity followed . Cossacks were sent with hetman ' s letters to many regions of Ukraine calling on Cossacks and Orthodox peasants to join the rebellion , the defence of Khortytsia was improved , arrangements were made to acquire and make weapons and ammunition , and emissaries were sent to the Khan of Crimea , İslâm III Giray . Initially , Polish authorities took the news of Khmelnytsky ' s arrival at the Sich and reports about the rebellion quite lightly . The two sides exchanged lists of demands : the Poles asked for Cossacks to surrender the mutinous leader and disband , while Khmelnytsky and the Rada demanded that the Commonwealth restore the Cossacks ' ancient rights , stop the advance of the Ukrainian Greek Catholic Church , yield the right to appoint Orthodox leaders of the Sich and of the Registered Cossack regiments , and remove the Commonwealth troops from Ukraine . These demands of Khmelnytsky were taken as an affront by the Polish magnates and an army headed by Stefan Potocki moved in the direction of the Sich . Had the Cossacks stayed at Khortytsia they might have been defeated as in many other rebellions . But this time , instead of waiting for the Poles , Khmelnytsky marched against them . The two armies met on 16 May 1648 at Zhovti Vody , where , aided by the Tatars of Tugay Bey , the Cossacks inflicted their first crushing defeat on the Commonwealth . This was repeated soon after , with the same success , at the Battle of Korsuń on 26 May 1648 . What made these Cossack successes different was the diplomatic and military skill of Khmelnytsky : under his leadership , the Cossack army moved to battle positions following his plans , Cossacks were proactive and decisive in their maneuvers and attacks , and most importantly , he not only managed to persuade large contingents of registered Cossacks to switch to his side , but also got the support of the Crimean Khan — his crucial ally for the many battles to come . Establishment of the Cossack Hetmanate . At Christmas 1648 , Khmelnytsky made a triumphant entry into Kiev , where he was hailed as " the Moses , savior , redeemer , and liberator of the people from Polish captivity . . . the illustrious ruler of Rus " . The Patriarchs of Jerusalem Paiseus who was visiting Kiev at this time referred to Khmelnytsky as the Prince of Rus , the head of independent Ukrainian state , according to the contemporaries . In February 1649 , during negotiations in Pereiaslav with a Polish delegation headed by senator Adam Kysil , Khmelnytsky declared that he was " the sole autocrat of Rus " and that he had " enough power in Ukraine , Podilia , and Volhynia . . . in his land and principality stretching as far as Lviv , Chełm , and Halych . " It became clear to the Polish envoys that Khmelnytsky had positioned himself not just as a leader of the Zaporozhian Cossacks , but of Ukraine , and stated his claims to the heritage of the Rus . A Vilnius panegyric in Khmelnytsky ' s honor ( 1650 – 1651 ) explained it this way : " While in Poland it is King Jan II Casimir Vasa , in Rus it is Hetman Bohdan Khmelnytsky . " After the period of initial military successes the state - building process began . His leadership was demonstrated in all areas of state - building : in the military , administration , finance , economics , and culture . With political acumen he made the Zaporozhian Host under the leadership of its hetman the supreme power in the new Ukrainian state , and unified all the spheres of Ukrainian society under his authority . Khmelnytsky built a new government system and developed military and civilian administration . During this time a new generation of statesmen and military leaders came to the forefront : Ivan Vyhovsky , Pavlo Teteria , Danylo Nechai and Ivan Nechai , Ivan Bohun , Hryhoriy Hulyanytsky . From Cossack polkovnyks , officers , and military commanders , a new elite within the Cossack Hetman state was born . Throughout the years , this elite preserved and maintained the autonomy of the Cossack Hetmanate in the face of Russia ' s attempt to curb it . But it was also instrumental in the onset of the period of Ruin that followed and eventually destroyed most of the achievements of the Khmelnytsky era . Complications . Khmelnytsky ' s initial successes were followed by a series of setbacks as neither Khmelnytsky nor the Commonwealth had had enough strength to stabilize the situation or to inflict a defeat on the enemy . What followed was the period of intermittent warfare and several peace treaties , which neither side put much faith in or cared to abide by . From the spring of 1649 on , the situation turned for the worse for the Cossacks , as the frequency of Polish attacks increased and they were becoming more and more successful . The resulting Treaty of Zboriv on 18 August 1649 was unfavourable for the Cossacks . This was followed by another defeat at the battle of Berestechko on 18 June 1651 , where the Tatars betrayed him again and even held the hetman captive . The result was a crushing defeat for the Cossacks and a high number of casualties ( estimated to be around 30 , 000 Cossacks ) , along with the Treaty of Bila Tserkva , which favoured the Polish – Lithuanians . That treaty was soon violated , and in the years that followed the two sides were almost in the perpetual state of warfare . In this situation the Crimean Tatars played a decisive role — not allowing either side to prevail . It was in their interests to keep both Ukraine and the Polish – Lithuanian Commonwealth from getting too strong and becoming an effective power in the region . Under the circumstances , Khmelnytsky started looking for another foreign ally . Even though the Cossacks established their " de facto " independence from Poland , the new state needed legitimacy that was essential in 17th century Europe , and this legitimacy could be provided by a foreign monarch . In search of a protectorate , Khmelnytsky approached the Ottoman sultan in 1651 and formal embassies were exchanged . The Turks offered vassalship similar to their other arrangements with contemporary Crimean Peninsula , Moldavia and Walachia . However , the idea of a union with the Muslim monarch didn ' t rest well with the general populace and the Cossacks from whom Khmelnytsky drew his support . The other possible ally was Orthodox Russia . They , however , remained quite cautious and stayed away from the hostilities in Ukraine . In spite of numerous envoys and calls for help from Khmelnytsky in the name of the shared Orthodox faith , the Tsar preferred to wait until the threat of a Cossack - Ottoman union in 1653 finally forced him to action . The idea that the Tsar might be favourable to taking Ukraine under his hand was communicated to the hetman and the diplomatic activity intensified . Treaty with Moscovy . After a series of negotiations , it was agreed that the Cossacks would accept the tsar ' s overlordship . To finalize the treaty , a Muscovite embassy led by boyar Vasili Buturlin came to Pereyaslav , where on 18 January 1654 the Cossack Rada was called and the treaty concluded . There is still no unanimity among historians as to the true intentions of both Muscovy and Khmelnytsky in signing this agreement . For Tsar Alexei Mikhailovich the treaty legitimized Moscow ' s claims to the territory of Kievan Rus ' and strengthened his influence in the region . For Khmelnytsky the Treaty of Pereyaslav offered first and foremost a legitimate monarch ' s protection and support from a friendly Orthodox power . There have been a number of conflicting opinions as to what kind of union Khmelnytsky had in mind , whether it was to be a military union , a suzerainty or a complete incorporation of Ukraine into the Tsardom of Russia . The two sides had somewhat different ideas of the treaty and the union , as exemplified by an incident during the oath of allegiance to the Tsar : the treaty was almost broken when the Moscovite envoy refused to reciprocate with an oath from the ruler to his subjects , as was the custom with the Polish king . At one point , for this reason , Khmelnytsky stormed out of the church and threatened to cancel the entire treaty . It was only after some consideration that this demand on the part of the Cossacks was rescinded and the treaty stayed . Due to both sides having different goals in Ukraine , the liberties that were allowed to Khmelnytsky due to his stature were denied to his successors . That , in the end , eventually led to the complete incorporation of Ukraine into the Tsardom of Moscovy and later into the Russian Empire . Final years . As a result of the Treaty of Pereyaslav the geopolitical map of the region had changed — a new player , Russia , entered the scene , and the Cossacks ' former allies , the Tatars , went to the Polish side . That intensified the conflict , as the Tatars were now unrestrained in their warfare against Khmelnytsky . Tatar raids depopulated whole areas of Ukraine . Cossacks , aided by the Tsar ' s army , took revenge on Polish possessions in Belarus , and in the spring of 1654 , the Cossacks drove the Polish from much of the country . To complicate the situation even further , another power joined the melee — Sweden . They were the old adversaries of both Poland and Russia , but did not attack Russia , instead being quick to occupy their share of Lithuania before the Russians could get there . That put Khmelnytsky into a delicate situation in regard to the Tsar , as he had been negotiating with the Swedes for some time , coordinating their attacks on the Commonwealth . Besides being hostile to Sweden in general , this also displeased Russia because Russia had its eyes on the Swedish Baltic provinces . In 1656 with the Commonwealth increasingly war - torn but also increasingly hostile and successful against the Swedes , the ruler of Transylvania , George II Rákóczi , also joined in - a last straw effort of Charles X of Sweden to save the war effort due to the massive Polish popular opposition against the Swedes . Under blows from all sides the Commonwealth only survived thanks to its steely unity in the face of destruction . Russia attacked Sweden in July 1656 when Sweden was deeply involved with its situation in Poland . That war ended in status quo two years later , but it complicated matters even further for Khmelnytsky , as his ally was now fighting his overlord . In addition to diplomatic tensions between the Tsar and Khmelnytsky , a number of other disagreements between the two surfaced , notably in regard to Russian officials ' interference in the finances of the Hetmanate and in the newly liberated Belarus . One thing that infuriated the hetman the most was the separate treaty the Tsar concluded with the Poles in Vilnius in 1656 . The Hetman ' s emissaries were not even allowed to attend the negotiations . That prompted Khmelnytsky to write an irate letter to the Tsar accusing him of breaking the Pereyaslav agreement . In his anger , Khmelnytsky compared Swedes to the Tsar , claiming that the Swedes were more honourable and trustworthy than the Russians . In addition to diplomatic tensions with Russia , the Cossack army with their Transylvanian allies in Poland suffered a number of setbacks . As a result , Khmelnytsky had to deal with a Cossack rebellion on the home front . Troubling news also came from Crimea , as Tatars , in alliance with Poland , were preparing for a new invasion of Ukraine . Though already ill , Khmelnytsky continued to conduct diplomatic activity , at one point even receiving the Tsar ' s envoys in his bed . On 22 July he suffered cerebral hemorrhage , became paralyzed after his audience with the Kiev Colonel Zhdanovich whose expedition to Halychyna failed due to mutiny within his army . Less than a week later , Bohdan Khmelnytsky died at 5 A . M . on 27 July 1657 . His funeral was held on 23 August , and his body was taken from his capital Chyhyryn to his estate at Subotiv for burial in his ancestral church . In 1664 a Polish noble Stefan Czarniecki captured Subotiv and ordered the bodies of the hetman and his son Tymish to be exhumed and desecrated . Khmelnytsky remembered . It is hard to overestimate Khmelnytsky ' s contribution and role in the history of Eastern Europe . He not only shaped the future of Ukraine but significantly changed the balance of power in Eastern Europe . As with any other prominent personality his role in the events and his actions were viewed differently by his various contemporaries , and even now different people sometimes have quite opposing views on his legacy . Khmelnytsky in Ukrainian history . In Ukraine , Khmelnytsky is generally regarded as a national hero and a father of the nation . A city and a region of the country bear his name . His image is prominently displayed on Ukrainian banknotes and his monument in the centre of Kiev is the focal point of the Ukrainian capital . There have also been several issues of the Order of Bohdan Khmelnitsky — one of the highest decorations in Ukraine and in the former Soviet Union . With all this positive appreciation of his legacy , even in Ukraine it is far from being unanimous . He is mostly criticised for his union with Russia , which in the view of some , proved to be disastrous for the future of the country . This particular view , among others , was expressed by a prominent Ukrainian poet , Taras Shevchenko , who was one of Khmelnytsky ' s very vocal and harsh critics . Furthermore his local reputation was damaged by his alliance with the Crimean Tatars , which permitted the latter to take a large number of Ukrainian peasants as slaves ( this may be interpreted as an illustration of the relative indifference of the cossacks as a military caste toward the ' kholopy ' , the lowest stratum of the Ukrainian people ) . The traces of this are still found in folk songs . On the balance , the view of his legacy in present - day Ukraine is more positive than negative , with some critics admitting that the union with Russia was dictated by necessity and an attempt to survive in those difficult times . Khmelnytsky in Polish history . Khmelnytsky ' s role in the history of the Polish State has been viewed mostly in a negative light . The rebellion of 1648 proved to be the end of the Golden Age of the Commonwealth and the beginning of its demise . Even though it would survive the rebellion and the period of Deluge that followed , within a hundred years it would be no more — its remains would be divided between Russia , Prussia , and Austria in the partitions of Poland . Many blamed Khmelnytsky for the decline of the Commonwealth . This view is contrasted with a far more comprehensive appreciation of Khmelnytsky ' s legacy by Polish historians , like Ludwik Kubala , who in his works compared him with Oliver Cromwell . A more balanced appreciation prevails — that the fundamental ills of the Commonwealth resulted in the rebellion that Khmelnytsky led . Khmelnytsky in Russian and Soviet history . In their assessment of Khmelnytsky ' s legacy the official Russian historiography stressed the fact that Khmelnytsky entered into union with Moscow ' s Tsar Alexei Mikhailovich with an expressed desire to " re - unify " Ukraine with Russia . This view corresponded with the official theory of Moscow being an heir of the Kievan Rus ' and thus a gatherer of its former territories . In this light Khmelnytsky was viewed as a national hero of Russia for bringing Ukraine into the " eternal union " of all the Russias — Great , Little and White Russia . As such , he was much respected and venerated in Imperial Russia . His role was presented as a model for all Ukrainians to follow — to aspire for closer ties with Great Russia . This view was expressed in a monument commissioned by the Russian nationalist Mikhail Yuzefovich , which was installed in the center of Kiev in 1888 The original variant of the monument ( created by Russian sculptor Mikhail Mikeshin ) appeared too xenophobic for the Russian authorities , as it was to depict a vanquished Pole , Jew , and a Catholic priest under the hoofs of the horse . A more moderate version was installed , but the inscription on the monument read " To Bohdan Khmelnitsky from one and indivisible Russia . " The view of Khmelnytsky as a prominent , positive figure in the Russian history is further displayed in Mikeshin ' s Monument to the Millennium of Russia in Novgorod , where Khmelnytsky is shown as one of Russia ' s prominent figures . Soviet historiography followed in many ways the Imperial Russian theory of re - unification while adding the class struggle dimension to the story . Thus , Khmelnytsky was not only praised for re - unifying Ukraine with Russia , but also for organizing the class struggle of oppressed Ukrainian peasants against Polish exploiters . Khmelnytsky in Jewish history . Jewish history ' s assessement of Khmelnytsky is overwhelmingly negative given that he had made eradication of Jews from Ukraine one of his goals . Indeed , between 1648 – 1656 , Khmelnytsky ' s rebels murdered many Jews . Stories about massacre victims who had been buried alive , cut to pieces , or forced to kill one another spread throughout Europe and beyond . These stories filled many Jews with despair , and resulted in a revival of the ideas of Isaac Luria , and the identification of Sabbatai Zevi as the Messiah . Orest Subtelny writes : Between 1648 and 1656 , tens of thousands of Jews — given the lack of reliable data , it is impossible to establish more accurate figures — were killed by the rebels , and to this day the Khmelnytsky uprising is considered by Jews to be one of the most traumatic events in their history . ON THE POLITICS OF BOHDAN KHMELNYTSKY AND THE COSSACK Further reading . OFFICERS BETWEEN 1648 AND 1657 . PhD Dissertation ( University of London , 1981 ) < http : / / aleph . ukma . kiev . ua / e - lib / V / Velychenko _ The % 20Influence . pdf >