Masakr Hmielnickog 1648.

U sklopu kozačke pobune protiv Poljaka, Kozaci su 1648. godine, pod vodstvom Bogdana Hmielnickog, počinili niz progona i ubojstava Židova, što će u židovsku povijest ući pod imenom - Masakr Hmielnickog.Pod parolom da su ih Poljaci prodali u roblje u ruke prokletih Židova, Kozaci su 1648-1649. poubijali na desetke tisuća Židova.

Prema Židovskim kronikama, pognulo je oko 100,000 ljudi, a oko 300 židovskih zajednica je uništeno. Izvori naglašavaju kozačku okrutnost te da su mnogi Židovi radije pobjegli na Krim, gdje su ih Tatari prodali u roblje, nego da padnu Kozacima u ruke. Za vrijeme ovog ustanka stradali su i Židovi i Poljaci (ustanak je bio okrenut protiv poljske dominacije), a zemljom su zavladali pustoš, glad i epidemije.

Najpoznatiji izvor za pogrom je: Nathan Hannover, Ponor beznađa (Jeven macula); njegov se opis ovih događaja temelji na vlastitim i iskustvima svjedoka. Njegova kronika uključuje opise mnogih zvjerstava, koje su se dogodile tijekom kozačkog ustanka. Nakon masakra, u mnogim je židovskim zajednicama postao običaj čitati iz ove kronike za vrijeme trotjednog razdoblja žalosti, koje prethodi 9. avu, kada se komemorira uništenje Hrama.

Dio svjedočenja o onome što se dogodilo u područjima Mogila, Zaslav i Nemirov, između 1648. i 1651.:
In the city of Mogila they slaughtered 800 nobles together with their wives and children as well as 700 Jews, also with wives and children. Some were cut into pieces, others were ordered to dig graves into which Jewish women and children were thrown and buried alive. Jews were given rifles and ordered to kill each other...They surround young women and, as they struggled to escape, cut their clothes from their bodies. Then they performed abominations on them until they died screaming....
They arrived... (disguised) as if they had come with the Poles... in order that he open the gates of the fortress... and they succeeded... and they massacred about 6,000 souls in the town... and they drowned several hundreds in the water and by all kinds of cruel torments. In the synagogue, before the Holy Ark, they slaughtered with butchers' knives... after which they destroyed the synagogue and took out all the Torah books... they tore them up... and they laid them out... for men and animals to trample on... they also made sandals of them... and several other garments".
Some were skinned alive and their flesh was thrown to the dogs; some had their hands and limbs chapped off and their bodies thrown on the highway to be trampled by wagons and crushed by horses; some had wounds inflicted upon them and were then thrown on the street to die a slow death. They tore open women and then whipped them forcing them to crawl to their deaths.... others were buried alive. The enemy slaughtered infants in their mothers' laps. They were sliced into pieces like fish.... The infants were hung on the breasts of their mothers. Some children were pierced with spears.

Ubrzo je Ukrajina postala neovisna, ali je ta epizoda bila kratkog vijeka: godine 1651., Hmielnicki je doživio poraz te je prisiljen potpisati sporazum po kojem nije dobio onoliko kontrole nad Ukrajinom, koliko se nadao. Zato 1654. uspijeva uvjeriti Kozake da svoju lojalnost iskažu ruskom caru. Rusija anektira Ukrajinu 1653. godine.