Today is the minor festival of Lag ba’Omer, which marks the end of a period of mourning that follows Passover. While this period of mourning is traditionally associated with a 2nd-century plague, some modern scholars believe its origins in part lie with episodes of anti-Jewish violence in medieval northern Europe that took place during this time of year. Once such instance was the outbreak of the Rindfleisch massacres in 13th-century Germany. Michael Freund writes:

The torment began on April 20, 1298, after the Jews of the German city of Röttingen were accused of “desecrating the host,” a popular medieval slander according to which Jews stabbed and defiled the wafer used by Catholics in their Sunday services.

As the accusation spread, a knight named Rindfleisch whipped up Röttingen’s locals into a frenzy and vowed to wipe out “the accursed race of the Jews,” claiming he had a mandate from heaven. Together with a mob, he proceeded to attack the city’s Jews, viciously slaughtering them and burning many at the stake. The marauding thugs then went from town to town, and in subsequent months they attacked a total of 146 Jewish communities, many of which were completely destroyed. With rare exceptions, local authorities and church officials did nothing to stop the slaughter.

Historians differ as to the number of Jews who were killed, with estimates ranging from 20,000 to as many as 100,000 men, women, and children.

While it is commendable that administrators of several universities finally called upon police to crack down on violent and disruptive anti-Israel protests, the actions they have taken may be insufficient. At Columbia, demonstrators reestablished their encampment on the main quad after it had been cleared by the police, and the university seems reluctant to use force again. The school also decided to hold classes remotely until the end of the semester. Such moves, whatever their merits, do nothing to fix the factors that allowed campuses to become hotbeds of pro-Hamas activism in the first place. The editors of National Review examine how things go to this point:

Since the 10/7 massacre, Columbia’s Jewish students have been forced to endure routine calls for their execution. It shouldn’t have taken the slaughter, rape, and brutalization of Israeli Jews to expose chants like “Globalize the intifada” and “Death to the Zionist state” as calls for violence, but the university refused to intervene on behalf of its besieged students. When an Israeli student was beaten with a stick outside Columbia’s library, it occasioned little soul-searching from faculty. Indeed, it served only as the impetus to establish an “Anti-Semitism Task Force,” which subsequently expressed “serious concerns” about the university’s commitment to enforcing its codes of conduct against anti-Semitic violators.

But little was done. Indeed, as late as last month the school served as host to speakers who praised the 10/7 attacks and even “hijacking airplanes” as “important tactics that the Palestinian resistance have engaged in.”

The school’s lackadaisical approach created a permission structure to menace and harass Jewish students, and that’s what happened. . . . Now is the time finally to do something about this kind of harassment and associated acts of trespass and disorder. Yale did the right thing when police cleared out an encampment [on Monday]. But Columbia remains a daily reminder of what happens when freaks and haters are allowed to impose their will on campus.