Nothing at all is known of either the patron or scribe of the Prato Haggadah, and little is known of its whereabouts from the time it was produced in Spain, around 1300, until the time it was acquired by the JTS Library in l964.

While the haggadah's text is written in accordance with the Spanish rite, at some point additional text, which included liturgical poems of the Ashkenazic rite, was added, most likely in Italy. A 1617 signature of an Italian church censor, Giovanni Domenico Carretto is proof that the manuscript actually was in Italy at the beginning of the seventeenth century.

Nothing further is known of the haggadah's history until 1928, when it was in the possession of Dr. Ludwig Pollak, a native of Prague living in Rome. A distinguished humanist and collector of classical art, literary manuscripts, books and Judaica, Dr. Pollak promised the haggadah to his friend Rabbi David Prato, Chief Rabbi of Rome. After disagreements with the Fascist authorities in the late 1930s, Rabbi Prato moved to Palestine. Dr. Pollak, his wife and son, along with other members of the Jewish community of Rome, were deported to Auschwitz, where they perished.

Dr. Jeonathan Prato in his home in Jerusalem with conservator Nellie Stavisky (October, 2004)

After the war, Rabbi Prato was recalled to his previous position in Rome and served the community until his death in 1951. Shortly after the Rabbi's demise, his only son Jeonathan, an Israeli diplomat en route to his post in Buenos Aires, was visited by the sister-in-law of Dr. Pollak in Rome. Knowing of Dr. Pollak's intention to donate the manuscript to the rabbi, she fulfilled the promise and gave the haggadah to the rabbi's only surviving heir. The Prato Haggadah was purchased by the JTS Library in 1964.