Between the 9th and 10th centuries, documents speak of a judeca, a Jewish neighborhood, with rented land, on which the Salerno Jews build their houses. The area is peripheral, almost outside the city proper, called "inter murum et muricinum," that is, between the ancient Roman-Byzantine wall and the new Lombard one of Arechi and Grimoaldo, between the current via Masuccio Salernitano and vico Giudaica. These lands are owned by the church of Santa Maria de Domno, later called Sancta Maria de Judeca, of the female Benedictine monastery of San Giorgio, and of the church of Santa Maria a Mare, which rests directly on the walls and on a torre, and subsequently took the significant name of Sancta Lucia in Iudicaria. At the beginning the houses are made of wood, easy to dismantle in case of non-renewal of the rent, but, over the centuries, they end up merging with the city walls, so much so that in 1271 we will see permission granted to Salomon de Tincta to open windows in the south wall of Salerno to light up his home.

That this neighborhood is "a separate area", almost outside the city, should not be surprising. We know that the relations of the Jewish community of Salerno with the authorities, secular and ecclesiastical, are quite good, at least until the 11th century, so much so that we find Jewish merchants, bankers and doctors at the service of very big guns, such as the one Shamar son of Abraham , officially commissioned in 1140 by the abbot of the monastery of Cava de 'Tirreni to collect the tithe from the Salerno markets. At the practical level, however, a sort of latent hostility remains, especially with the secular authorities and the Christian population, so much so that, for the assizes of Capua in 1220 presided over by Frederick II, the Jews will be obliged to make itself recognizable by wearing a blue dress and a long beard; it is not a question of racial anti-Semitism, typical of modernity, but of anti-Judaism, purely religious aversion, considering the Jews as diabolical enemies of the Christian faith, guilty of killing Christ. So much so that a custom documented since the twelfth century sees the head of the Salerno synagogue, on the eve of the feast of the translation of the relics of St. Matthew, kneel in front of the door of the lions and offer his head as a lectern to support the volume of the Gospel at the time of its reading during the service. On the other hand, the attitude of the clergy towards them is tempered by the thought of S. Agostino, who argued that the Jews, with their mere presence, testified to the truth of Christianity, and therefore should not be done to them by evil.

The peak of the flowering of the Salerno Jewish community starts from the period between the second half of the 10th century and the end of the 11th century. The Jews of Salerno carry out activities of great importance, many of which are related to the textile sector, such as weaving, dyeing and manganizing of fabrics, whose earnings are so greedy that Archbishop Alfano II requested and obtained in 1090 from Duke Ruggiero Borsa the right to tax them. Then there are the activities related to the tanning, treatment and dyeing of leathers, including the production of skins for the transport of oil into goatskin, of which the Jews even have a monopoly by concession of Duke William II of Puglia in 1121 , and that the abbots of S. Maria de Domno, in 1031, even included in the canon the use of a well together with a silk track. On the other hand, this type of wineskins have been in use in Salerno until very recent times, as well as kosher-type slaughter, carried out by cutting the animal's throat to make it quickly lose consciousness and to bleed it, and that the Jews already practiced at the beginning of the twelfth century, if the privilege of Duke William allows them to be the only ones to be able to slaughter in the city.

And then, of course, in the Salerno Jewish community there are also merchants and bankers, since, among the various taxes, there is also the "portulaticum", a duty for the transport of goods by sea; it trades with Muslim countries, and Salerno is a port frequented by Jewish merchants from all over the Mediterranean, as well as by intellectuals and especially by doctors. In one of the documents of the Ghenizah (11th century Jewish archive found in Cairo) it is stated that for the Jewish merchants of Tunisia it was possible to spend an entire winter in Salerno before resuming trade in the Mediterranean.

Benjamin of Tudela testifies to this around 1161, who from Spain visits other synagogues scattered throughout Europe, and in his Itinerarium documents that in Salerno ("where the sons of Edom - the Christians - have medical schools", he adds significantly) there is a community of about six hundred people, the largest in southern Italy, which hosts many talented doctors. Not only that, Beniamino di Tudela also points out a college of rabbis, of which he also gives the names: Judas son of Isaac, Solomon ha-Cohen originally from Siponto, Elijah whom the author calls "the Greek", Abraham of Narbonne and Hamon . A rabbis college presupposes the presence of a synagogue, and a "major synagogue", which, in the language of the Jews of the tribe of Judah of the period following the destruction of the second temple in Jerusalem in 70 and then in 132, indicates a synagogue equipped of a college of masters; many believed to place this synagogue near the church of S. Lucia.

This culturally lively community was to host, between 1250 and 1279, an authentic luminary of knowledge in all fields, Mosè Ben Shelomoh (also known as Mosè da Salerno), honored even by his contemporaries as the "third Moses", after that biblical and Moses Maimonides; a sepulchral plaque dated to 1279 and dedicated to Moses ben Shelomoh found in the church of Santa Lucia, seems to confirm this. In Salerno, Moses, a doctor and translator, dedicated himself to the translation and commentary of Hebrew literature, also working with Christians: for example, he comments on the "Guide of the Perplexed" by Mose Maimonides in collaboration with the Dominican Nicola Paglia da Giovinazzo (blessed for the church). On the other hand, Christian theologians, and the papal court itself, have been in contact with Jewish scholars for at least a couple of centuries.

This fairly peaceful coexistence suffered a first blow with the arrival of the Angevins. Towards the Jews, the d'Angiòs have an ambiguous attitude: if often and willingly the court hosts Jewish intellectuals and translators such as the doctor from Agrigento but from Salerno by training Faraj ibn Sālim (also called Ferragut), on the other hand it tries in every way to win the Jews for Christ, by hook or by crook. One episode in particular reveals this climate of tension. In 1292, the inquisitor general of the Kingdom, the Dominican Bartolomeo dell'Aquila, was disturbed for two serious events that occurred in the city: the circumcision and purification of two Jews previously converted to Christianity (probably two "converts on the facade "Who wanted to return to their original faith). The Inquisitor's sentence is the destruction of the synagogue from its foundations; This destruction, however, does not happen thanks to the intercession of the rabbis, who get the building to be sold and the proceeds given in alms.

With the passage of time, however, the tension subsides, especially with the arrival of the Aragonese in the 15th century. Jews are protagonists of the Neapolitan Renaissance, Jewish intellectuals, especially doctors, attend the Academy created by Giovanni Pontano in 1471, and they themselves create intellectual circles, like that of the Abravanel family. It is a rich and powerful family, who lives at the Neapolitan court, and even obtained from Charles V, in 1520, the authorization to open a bank in Salerno, in the very central "ruga aromatariorum" (the current Via Giovanni da Procida). In the circle of Abravanel, Plato is studied, literary works are printed in Hebrew, Judas Abravanel, known as the "Jewish Lion", writes his Dialogues of Love, of neo-Platonic inspiration; their home is frequented by intellectuals of the caliber of Agostino Nifo, and even of the Augustinian Girolamo Seripando, future archbishop of Salerno.

In 1532, however, Charles V appointed Don Pedro de Toledo as viceroy for southern Italy, who exercised a powerful grip in all fields; for the Jews, in 1541, he applied the same regime as in the mother country, for which the Jewish communities are obliged to convert or to leave. Not even the influential Abravanel can do anything against this decree, which in fact represents the end of the Jewish community of Salerno. They themselves will be forced to take refuge in Ferrara.