The Twentieth of Sivan is a historic

Jewish fast day A ta'anit or ta'anis ( Mishnaic Hebrew: תענית) is a fast in Judaism in which one abstains from all food and drink, including water. Purposes A Jewish fast may have one or more purposes, including: * Atonement for sins: Fasting is not cons ...

, first instituted by

Rabbeinu Tam Jacob ben Meir (1100 – 9 June 1171 (4 Tammuz)), best known as Rabbeinu Tam ( he, רבינו תם), was one of the most renowned Ashkenazi Jewish rabbis and leading French Tosafists, a leading ''halakhic'' authority in his generation, and a gr ...

in 1171. It originally commemorated that year's massacre at

Blois Blois ( ; ) is a commune and the capital city of Loir-et-Cher department, in Centre-Val de Loire, France, on the banks of the lower Loire river between Orléans and Tours. With 45,898 inhabitants by 2019, Blois is the most populated city of the ...

in France, the first blood libel in continental Europe. The day was later also marked to commemorate the

Cossack riots The Cossack riots were pogroms carried out against the Jews of modern Ukraine during the 1648 uprising of the Cossacks and serfs led by Bogdan Khmelnytsky (or the "Hamil of Evil" as he was called by the Jews) against the Polish–Lithuanian Comm ...

of 1648–49 in Poland-Lithuania, instituted by the

Council of Four Lands The Council of Four Lands ( he, ועד ארבע ארצות, ''Va'ad Arba' Aratzot'') in Lublin, Poland was the central body of Jewish authority in Poland from the second half of the 16th century to 1764. The first known regulation for the Council ...

in 1650. After World War II, suggestions were made to observe it as a Holocaust memorial day, but this was not widely adopted. In 1948,

Tzvi Pesach Frank Tzvi Pesach Frank (20 January 1873 – 10 December 1960) (Hebrew: הרב צבי פסח פרנק) was a renowned halachic scholar and served as Chief Rabbi of Jerusalem for several decades (1936-1960). Biography Frank was born in Kovno, Viln ...

proposed to use the day to commemorate the fall of the Jewish Quarter in the

Battle for Jerusalem The Battle for Jerusalem took place during the 1947–1948 civil war phase of the 1947–1949 Palestine war. It saw Jewish and Arab militias in Mandatory Palestine, and later the militaries of Israel and Transjordan, fight for control over t ...

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References

{{reflist Medieval anti-Jewish pogroms Jewish fast days Sivan observances Ashkenazi Jews topics