Among his works are The Jews in Medieval Assisi 1305-1487: A social and economic history of a small Jewish community (1979), Il vino e la carne. Una comunità ebraica nel Medioevo ('Wine and Meat. A Jewish Community in the Middle Ages', 1989), Mostri giudei. L'immaginario ebraico dal Medioevo alla prima età moderna ("Jewish Monsters. The Jewish Imaginary from the Middle Ages to the Early Modern Era", 1996) and Mangiare alla giudia. La cucina ebraica in Italia dal Rinascimento all'età moderna ('Eating Jewish style. Jewish Cooking in Italy from the Renaissance to the Modern Age', 2000).
Passovers of Blood: The Jews of Europe and Ritual Murders
Toaff's most recent book, Pasque di sangue. Ebrei d'Europa e omicidi rituali ("Passovers of Blood: The Jews of Europe and Ritual Murders"), was published in February 2007. The book analyzes the cultural and historical background to a notorious medieval trial regarding accusations of the ritual murder of a child by some Jews for the purposes of Passover, accusations which the consensus of scholarship has dismissed as a blood libel against Jews. The book sparked intense controversy, including calls for him to resign from or be fired from his professorship, the questioning of his research, historical method(s), and motives  as they relate to his writing of the book, threats to his life , and demands that he be prosecuted. Despite having earlier promised not to give in to pressure and defend his work "even if crucified" , Toaff recanted  and pulled the book from circulation.
The Argument of Passovers of Blood- Chapter 1
Toaff opens his book with a detailed vignette of the arrival in Venice from Rome of the philosemitic Holy Roman Emperor Friedrich III Habsburg of Innsbruck. It was his third visit to the city, and his arrival was met by an influx of numerous visitors, merchants, adventurers, clerics and relic-hawkers, all keen to obtain certificates attesting to their merits, services and learning. Among the various groups was a delegation of Ashkenazi Jews, leaders of a community that, over the preceding century, had emigrated in considerable numbers from German lands towards northern Italy where the expanding commercial empire of Venice offered prospects of prosperity and relief from the afflictions they had suffered in their northern homelands, in waves of antisemitic pogroms from the age of the Crusades to the Black Death.
Venice had in its employ a spy and intriguer, the Cretan adventurer and businessman David Mavrogonato, regarded as a malshin (moser) by the Jews of his native Heraklion, who was engaged in furthering Venetian interests in the Ottoman Empire's dominions in the Aegean. He, and his bodyguard and successor Salomone of Piove, enjoyed considerable privileges for services they rendered to the Council of Ten. Both attempted to employ Jewish physicians in an attempt to assassinate Mehmed II. The cameo role played by these two allows Toaff to touch on the politics of intrigue within the larger Jewish community. As Mavrogonato and Salomon of Piove acted on Christian Venice's behalf to kill a Turkish Sultan, so one of Salomon's henchman, Salomon Fürstunger, connived with Pavia's powerful banker Mendele b.Abraham to get an Italian priest to assassinate by poisoning those responsible for the trial at Trento, over the case of Simon of Trent, which had led to the burning at the stake and decapitation of many Jews in 1475.
In examining the condotte, pacts negotiated between Jewish leaders and the local authorities stipulating the duties and conditions under which the Jewish communities were given the rights of residency, Toaff elicits a significant difference in cultural values between the native Italian Jewish communities, and those hailing from the German-speaking world beyond the Alps. The Ashkenazi retained their deep suspicion of the Christian world which, in Germany, had caused them grievous injury, even within the, at the time, more hospitable world of northern Italy. In various agreements, they asked for and obtained strict guarantees from their hosts against forced conversion by friars and priests, the right to use kosher foods, the right to physical safety, severe punishments to be inflicted on any one who should harm them, and freedom from having their assets seized. Strict conditions were negotiated to govern the reliability of witnesses in the case of criminal charges being laid against them. They obtained the right to be allowed to follow their own religious observances with 'zealous scruple'. In some condotte, the authorities were asked, and consented to, expelling any Jews from the city (Gemona) who converted to Christianity.
Both groups competed as suppliers of credit, but the older Italian Jewish communities quickly lost out to the new Yiddish-speaking Ashkenazi, and were forced to close down their banking operations in many northern areas in consequence. Toaff describes entrepreneurs from these Ashkenazi communities as brash with the new power of the financial authority they had expeditiously acquired in a mere five decades after their arrival:-
'(They were) self-confident and often arrogant and insolent in their relationships with rulers, observing laws only when it was strictly necessary or too dangerous to act otherwise.'
Salomon of Piove's two sons, Marcuccio and Salamoncino, outshone their father in their rash adventurousness and bold wheeling and dealing. The first was distinguished for his braggart haughtiness - he was defined by Venetian authorities as fidelis noster civis, and was assured of that city's protection - sufficiently so to boast of taking on and beating any Christian who might prove bold enough to mess around with him. The other son, Salamoncino, took care of that grey area where shady business ventures and the criminal underworld rubbed elbows., attempting to assassinate Mehmed 11, dealing in counterfeit goods and forbidden trade, and fleecing the Jews of Padova, rabbis, widows, students and the poor, of their savings. When his henchman David Schwab, hit by a cherem by a rabbinical victim, sought arbitration, Salamoncino hired an assassin to kill one of the other members of the swindling consortium, Aaron of Wil. The attempt failed, Salamoncino's role was discovered. He freely confessed to his Venetian protectors and was imprisoned for 6 months and banned for 4 years from Venice. After one more imbroglio he passes from history.
Tobias of Magdeburg, one of the doctors visiting Venice in search of a conferment of an imperial recognition from Frederick III in 1469, gave testimony linking the German Jews who had flocked to that city in the Emperor's train, with the figure of David Mavrogonato. According to his testimony at the Simon of Trent trial, Mavrogonato had imported, perhaps from Cyprus, large quantities of both sugar and blood for the Venetian market. Specifically, Tobias testified that the German Jews were keen to procure from the daring Cretan trader the blood of Christian children, not for confectioning rare medicines, but rather for obscure magical religious rites. Mavrogonato, wary of the dangers of direct involvement, delegated negotiations to a certain charlatan named Hossar, i.e. Asher of Cologne,  According to further testimony by Israel Wolfgang, a double-dealing opportunist, powdered blood from Mavrogonato's shipment had been used in preparing the wine and unleavened bread for the Passover feast in Salomon of Piove's home, in 1471, where he was guest. 
Reception and reactions
According to press reports, Toaff claims in his book that some Christian children may have been killed by "a minority of fundamentalist Jews of Ashkenazi origin." In an interview with Haaretz Toaff said: "Over many dozens of pages I proved the centrality of blood on Passover," Toaff said. "Based on many sermons, I concluded that blood was used, especially by Ashkenazi Jews, and that there was a belief in the special curative powers of children's blood. It turns out that among the remedies of Ashkenazi Jews were powders made of blood." The article also states that: "Although the use of blood is prohibited by Jewish law, Toaff says he found proof of permission given by a highly restricted school of Ashkenazi rabbis to use blood, even human blood. 'The rabbis permitted it both because the blood was already dried, and because in Ashkenazi communities it was an accepted custom that took on the force of law.'"
The book received a hostile academic reception. Johannes Heil, Professor of the History, Religion and Culture of European Jewry at the University of Heidelberg, said:
- "The result is appalling: either the book is a result of the utter naïveté of a historian who has hardly ever looked beyond the narrow confines of his academic speciality, the social history of Italian Jewry, or it is a deliberate, deeply cynical attempt to get a hearing for his ideas beyond the narrow circle of specialists." 
Dr. Amos Luzzatto, former president of the Union of Italian Jewish Communities, has said, "I would expect a more serious statement than 'it might have been true.'" He also expressed dismay at the sensationalism with which Corriere della Sera, Italy's leading daily, treated the issue.
Twelve of Italy's chief rabbis in a press release refuting Toaff's claims declared: "It is totally inappropriate to utilize declarations extorted under torture centuries ago to reconstruct bizarre and devious historical theses."
Roman Catholics from the town of Trent, near the Austrian border, commemorated Simonino's "martyrdom" for five centuries, until, in 1965, the Vatican published the Nostra Aetate, which aimed at extirpating antisemitism from Catholic doctrine. The Bishop of Trent signed a decree proclaiming that the blood libel against the city's Jews of that city was unfounded.
A preliminary refutation, including interviews with Italian scholars, appeared on 11 February 2007 in the Italian newspaper Corriere della Sera.
Writing in the same newspaper, Prof. Ronnie Po-chia Hsia states: "There is plenty of evidence to suggest hatred between Jews and Christians, as many scholars have demonstrated regarding the Middle Ages. It is, however, quite a leap of imagination to take testimonies obtained under torture and to construct a hypothetical reality based on unrelated circumstantial facts. It may be true that dried blood or other exotic ingredients were used in popular medicine, Jewish or Gentile - not being an expert on the history of medicine, I remain open-minded on this; but it is sheer blind logic to jump to the conclusion that Jewish groups might have used Christian blood for ritual practices."
Kenneth Stow, Professor Emeritus of Jewish History at the University of Haifa, wrote: "To disparage this book is not, as some have suggested, to challenge academic freedom. It is to decry bad historiographical method."
According to David Abulafia, Professor of Mediterranean History at the University of Cambridge, "... the significance of blood in Christian culture, and in particular the significance of the Eucharistic sacrifice, is largely ignored as an explanation of the fantasies, for such they were, about Passover rituals, fantasies in which the unleavened bread and wine became explicit negations of the body and blood of Christ. The blood libel has played a particularly nefarious role in the history of anti-Semitism."
Withdrawal from circulation
On February 14, 2007, Ariel Toaff said in a statement that he ordered the Italian publisher of his book to freeze distribution of his book so that he can "re-edit the passages which comprised the basis of the distortions and falsehoods that have been published in the media."
A week after its publication, Ariel Toaff withdrew the book from circulation, in order to "re-edit the passages which comprised the basis of the distortions and falsehoods that have been published in the media"
Second Edition (2008)
A revised, second edition of his work appeared in February, 2008. Toaff now concedes that the accusations of ritual murder, as a common Jewish practice, were entirely Christian fabrications,. However, Toaff maintains that it is possible that some radical Jews may have actually killed on ritual purpose, or for resentment against Christian persecution .
- ↑ S.Buttaroni, S. Musial (eds.) Ritual Murder Legend in European History, Krakow, Nuremberg, Frankfort, 2003 p.12 reads:'It is important to state from the very beginning that Jewish ritual murder never took place. Today proving such theories wrong is not the goal of scientific research'. Cited Toaff, Pasque di sangue 2007 p.225 n.2
- ↑ 'molto favorevole agli ebrei', as Elia Capsali, then Rabbi of Heraklion, noted and as translated by Toaff p.20
- ↑ A.Toaff, Pasque di sangue Il Mulino, Bologna, 2007 p.29
- ↑ Toaff, Pasque di Sangue, ibid.p.36
- ↑ Toaff, Pasque di sangue ibid. pp.45,47
- ↑ known in Venice as the bearded Jew el Zudio de la barba (p.47), and gaoled once for selling 'alchemical silver' by fraudulent means
- ↑ Toaff says Wolfgang's testimony on this Asher is confirmed by Venetian archives (p.47). But elsewhere he notes that this convert, formerly Israel of Brandenburg, was someone always ready to exploit hearsay 'to furnish loquaciously many tales to his voracious and powerful (Christian) interlocutors' Toath ibid.p.72
- ↑ Toaff ibid.p.46. Powdered blood was an expensive ingredient in many medicines at the time, and commerce in it did not imply a human provenance.
- ↑ 9.0 9.1 Bar-Ilan prof. defiant on blood libel book 'even if crucified' (Haaretz)
- ↑ Ariel Toaff and the Legend of Ritual Murder. (University of Heidelberg)
- ↑ 11.0 11.1 Historian gives credence to blood libel By LISA PALMIERI-BILLIG. (Jerusalem Post) February 7, 2007
- ↑ (Italian) Pasque di sangue, le due facce del pregiudizio «Omicidi rituali: manca la prova. Toaff legge acriticamente i testi» ARCHIVI Anna Esposito e Diego Quaglioni contestano la nuova interpretazione dello storico. (Corriere della Sera) 11 febbraio, 2007
- ↑ The real blood of Passover (Haaretz)
- ↑ 14.0 14.1 Blood Libel: Ariel Toaff's Perplexing Book By Kenneth Stow (HNN)
- ↑ "Blood libels are back" by David Abulafia (Times Literary Supplement) February 28, 2007
- ↑ 16.0 16.1 'Blood libel' author halts press by MATTHEW WAGNER AND AP (The Jerusalem Post) Feb. 14, 2007
- ↑ Scholar Pulls Book Revisiting Blood Libel - Says Press Distorted His Work, Pledges Proceeds to ADL by Gabriel Sanders (The Forward) February 16, 2007
- ↑ Historian recants theory that Jews killed Christian child in ritual murder
- ↑ La Stampa.it review of the second edition
- Sabina Loriga, "The Controversies over the Publication of Ariel Toaff's "Bloody Passovers"," Journal of The Historical Society, 8,4 (2008), 469-502.
- Commentary by Johannes Heil of the University of Heidelberg
- Commentary on Toaff's Book on Blood Libel (Haaretz)
- Article on Toaff and the Jewish-Italian Community (Haaretz)
- A blood-stained version of history (Haaretz)
- Toaff fights for his good name (Haaretz)
- MKs demand the author of blood libel book be prosecuted (Haaretz)
- Professor's Claim Of Truth To 'Blood Libel' Plays Into Hands Of Anti-Semites -- from the ADL
- "Jews Still Use Christian Blood to Bake Passover Matzos" - excerpts from an interview with Egyptian researcher Muhammad Al-Buheiri, which aired on Nile Culture TV on February 25, 2007 (MEMRI TV)