About one hundred Jewish families live in Trieste during the Middle Ages, many of them coming from transalpine countries.
During the 15th century reference to the community becomes more frequent and precise, registers of documents and minor proceedings are proof of commercial activities and the money lending business of Jewish families.
In the 1500s signals of hostility among the population directed against Jews are starting to appear. Emperor Charles V rises to their defence by decreeing acts of protection which confer a series of privileges to Jews in Trieste and which are kept up also by the Austro-Hungarian monarchs.