The origins of the lagoon's first Jewish community are, to a large extent, unclear. We do know for certain that Jews began trading on the Rialto some time around the 10th century. In 932 Doge Candiano 11 called upon Henry 1 of Germany to convert forcibly all the Jews in his kingdom or else expel them; and the prohibition of the slave trade issued in the year 960 included a ban - clearly inspired by economic motives - on Venetian ships carrying Jewish passengers to the Orient. However, as it rose in economic power. the Serenissima was worried more about commercial than religious rivalries. and was quite willing to tolerate the passage of Levantine merchants and Ashkenazi moneylenders.
Recent historical research has given the lie to the claim that the Jews were a constant presence in Venice in the early Middle Ages. The picture it paints is one of a 'city without Jews', which has once again raised the question of the origin of the name of the Giudecca (the long narrow island - once called Spinalonga - opposite St Mark's which. tradition has it, was where the city's Jewish community lived from the l l th to the 13th century).
There is no certain proof that the name derives from a Jewish connection. and a more plausible theory explains Giudecca as deriving from the Venetian word zudegà (tried or judged). There is, however, an oral tradition concerning two synagogues on the island (supposedly only demolished in the 18th century), while in the 19th-century a plaque with a Hebrew inscription was discovered on the island near the church of the Zitelle. The question is far from being settled, despite the vast amount of documents on the history of the Jewish community in Venice (particularly for the ghetto period).