The Chmielnicki Massacres (Gezerot Tach ve-Tat)

In the spring of 1648 Hetman Bohdan Chmielnicki raised the Zaporozhian Cossacks against Polish rule and allied with the Crimean Tatars. The revolt struck at Polish nobles, the Catholic Church and the Jews—leaseholders and estate managers whom the peasantry saw as the lords' agents. Jewish communities in the rebels' path were destroyed entire.

The best known was Nemirov. On the 20th of Sivan 1648 the Cossacks entered by deceit, raising Polish banners; the townsmen opened the gates. Thousands died, among them the community's rabbi, Rabbi Yechiel Michel. Then came Tulchyn, where the Polish garrison handed over the Jews to save itself and was slaughtered in turn; then Polonnoye, Bar, Ostroh, Kremenets. Those not killed outright were sold to the Tatars, and the communities of Istanbul, Salonika and Venice spent years ransoming captives.

Contemporary sources give enormous casualty figures, up to hundreds of thousands; modern historians speak of tens of thousands killed and some three hundred communities destroyed. Confident, prosperous Polish Jewry never fully recovered, and thousands of refugees moved west, reshaping the communities of Germany, Moravia and Holland.

The Council of Four Lands set the 20th of Sivan as a fast day. And the sense that the world was collapsing and redemption must come at once prepared the ground, fifteen years later, for Shabbetai Zevi.