The Twentieth of Sivan, designated by sages in two different eras to be a day of fasting and commemoration, marks tragedies that befell the Jews of Europe in the Middle Ages up to the Holocaust and was, until the Second World War, communally observed by European Jewry.
The Twentieth of Sivan was originally declared a day of fasting and commemoration in 1171. Tragedy had struck the Jewish community of Blois, France. The blood libel, which had been leveled on several occasions in England, had made its way to France. A local Christian claimed he saw a Jew throw the corpse of a child into the river Loire. The corpse was never found, but the testimony was accepted.
The town’s approximately 40 Jews were arrested and offered the choice of baptism or death. Despite the threats and torture, they did not yield. On the twentieth day of Sivan, thirty-two Jews, seventeen of them women, were burned at the stake.
In a letter about this tragedy written by the rabbinic scholar Ephraim Ben Yaakov of Bonn, the Twentieth of Sivan was decreed by the greatest Torah sage of that era, Rabbeinu Meir Tam, as a fast day for Jews living in France, the Rhineland and England.
The letter states that Rabbeinu Tam wrote letters to Jewish communities declaring this day to be one of “atonement.”
The murder of Jews in Blois was followed by many similar tragedies. Blood libels would bring in their wake immense suffering and torment to Jewish communities throughout Europe. Many Jews migrated to Eastern Europe where they continued to observe the Twentieth of Sivan.
Eventually, the Jews of Eastern Europe would also be compelled to observe this date of remembrance.
In 1648, the Ukrainian nationalist and Cossack leader Bogdan Chmielnicki incited a rebellion against Poland, which ruled over the Ukraine, and Polish landlords. Chmielnicki’s forces, combined with their Tartar allies of Mongolia, routed the Polish army at Yellow River on May 19 and Hard Plank on May 26.
The Polish defeat was a disaster for Ukrainian Jews, who now faced a major catastrophe. Chmielnicki’s Cossacks continued to attack Polish forces and then unleashed their fury against the Jews of the Ukraine and surrounding areas. Entire Jewish communities were wiped out, and hundreds of thousands of Jews were murdered, severely wounded, or left to starve to death.
The first reported attack against a large Jewish community was in the city of Nemirov. Jews from surrounding villages had gathered there for refuge. As Cossack troops neared Nemirov, the Jews locked themselves inside the city walls. As the soldiers drew near they unfurled Polish flags to give the impression they were Polish troops coming to the rescue.
The Poles in the city were notified of the ruse and collaborated with the Cossacks in order to save their own lives. They told the Jews guarding the gates that the approaching soldiers were indeed Polish and that they should open the gates.
The Cossacks entered the city with drawn swords, and the slaughter began. More than six thousand Jews were martyred that day. After Nemirov the Cossacks attacked Tulshin, Polannoe, Ostrog and Zaslow.
In the winter of 1650, rabbinic and lay leaders known as the Council of the Four Lands gathered in Lublin and declared the Twentieth of Sivan, the day the city of Nemerov had been attacked, a day of fasting and commemoration for the many martyrs of the Chmielnicki pogroms.
Massacres by Ukrainian nationalists continued long after Chmielnicki’s death in 1657. A series of attacks in the eighteenth century, including the Gonta massacres of 1767-1768, resulted in the deaths of tens of thousands of Jews. Pogroms were again unleashed in 1881 and 1903.
In 1919, a civil war positioned Ukrainians in pursuit of independence against both the Red Army and anti-Soviet Russians. Once again Ukrainian Jewry was caught in the middle, suffering horrific massacres. More devastation was still to come; in the early 1940’s, Ukrainian nationalists eagerly assisted the Nazis in killing Jews.
The blood-libel massacre in Blois and the pogroms in the Ukraine were separated by some five hundred years, but Rabbi Yom Tov Lippmann Heller, also known as the Tosafot Yom Tov, declared that the Selichot prayers composed in commemoration of the victims in France in the twelfth century be recited as well for the victims of Chmielnicki.