Along with all other current, post-biblical Jewish month names, Iyar was adopted during the Babylonian captivity. In the Babylonian calendar its name was Ara? ?ru, which can be interpreted as "month of blossoming".
15 Iyar (1727) - Jews expelled from Ukraine by Empress Catherine I a few months prior to her death.
15 Iyar (1883) - Pogrom in Rostov-on-Don with the encouragement of local Russian officials.
15 Iyar (1939) - The Nuremberg laws, depriving Jews the rights citizenship, were passed by the government of Nazi Germany in 1935. In 1939, on the 16th of Iyar, the laws went into effect in Nazi-allied Hungary.
18 Iyar (circa 120 CE) - A plague which killed 24000 of Rabbi Akiva's disciples ceases.
18 Iyar (Second century CE) - Death of Shimon bar Yochai On the day of his death--Iyar 18, the 33rd day of the Omer Count--Rabbi Shimon gathered his disciples and revealed many of the deepest secrets of the divine wisdom, and instructed them to mark the date as "the day of my joy."
18 Iyar (1690) - Ettingen Jews acquitted of a blood libel, avoiding the danger of the decree to destroy their synagogue were they to be found guilty. The local Jews celebrated this day as a local "Purim" celebration-day of thanksgiving.
18 Iyar (1948) - Hurva Synagogue captured and dynamited by the Arab Legion of Jordan during the battle for Old Jerusalem. The synagogue was built by the group of disciples of the Vilna Gaon who immigrated from Lithuania in 1864. The synagogue was built on the ruins of the synagogue built by Judah HeHasid) and his disciples in 1700, which was destroyed by Arab mobs in 1721. It was therefore named the "Hurvat Rabbi Judah HaChassid"--the ruins of Rabbi Judah the Chassid, or simply "The Hurva"--The Ruin.
19 Iyar (1293) - Death of Meir of Rothenburg in his cell in Ensisheim Fortress where he had been imprisoned for ten years in an attempt to exact a huge ransom from the Jewish community. The money had been raised, but Rabbi Meir refused to have himself redeemed, lest this encourage the hostage taking of other Jewish leaders. (see Adar 4)
20 Iyar (1288) - Thirteen Troyes Jews burned at the stake by the Inquisition for supposedly murdering a Christian child. The thirteen Jews chosen were from among the richer members of the community. Jews were also killed in a "blood libel" in Neuchâtel, Switzerland on this date.
20 Iyar (1942) - All pregnant women in Kovno Ghetto sentenced to death by the Nazis.
22 Iyar (1731) - Jewish books begin to be searched for and confiscated by Giovanni Antonio Costanzi, the Vatican librarian and author of a catalogue of the Vatican's Hebrew manuscripts, in all the Jewish quarters throughout the Papal States. More confiscations continued over the next twenty years.
25 Iyar (1096) - Cologne Jews saved - During the First Crusade, the crusaders are locked out of the city in the commune of Cologne in the Rhineland and local Jews are saved, following the orders of the local bishop to close the gates to the city. In a number of local provinces, where the local bishop tried to avert the masses from harming the Jews, the bishop would have to escape for his own safety.
26 Iyar (1945) - 26 of Iyar - Day of Liberation and Rescue has been established as an official day to remember the date of the liberation from Nazi Germany, 26th of Iyar in the Hebrew calendar. The holiday was initiated by German Zakharyayev, Gorsky-Kavkazi Jewish philanthropist and businessman, and supported by Rabbis of Europe and Israel. The day was also recently accepted by the Israeli government.
26 Iyar (1945) - Theresienstadt concentration camp liberated by the Soviets.
In Arabic, Ayyar or Eyyar (Arabic: ) refers to the month of May.
^Muss-Arnolt, W., [www.jstor.org/stable/3259081 The Names of the Assyro-Babylonian Months and Their Regents], Journal of Biblical Literature Vol. 11, No. 1 (1892), pp. 72-94 , accessed 10 Aug. 2020