The economic and political crisis of the Serenissima was also reflected in the decline of the Jewish community as the fiscal burden imposed upon the various nazioni became heavier and heavier. From the second half of the 17th century onwards the Università degli ebrei was unable to meet the needs of the credit market from the resources of its own members alone, and so had to resort to external capital, thus accumulating quite substantial debts. And the decline of the status of Venice encouraged members of the community to emigrate to the ports of the Tyrrhenian Sea and to Amsterdam in search of more favourable living conditions.
As a consequence, even the marvellous cultural vitality that had produced the musical academies and literary circles of the early part of the century was irreversibly undermined. Around 1660 Sabbatai Zevi of Smyrna (1626-76) declared himself to be the Messiah and a new wave of mysticism swept through the ghettos of Europe. The Venetian community's response ranged from the prudent caution of the local rabbis to irrational enthusiasm.
In the midst of all this confusion Sabbatai fooled everyone by converting to Islam. The wave of mysticism soon died down, and the Jews of Venice had to concentrate on a very critical situation as the Serenissima went into terminal decline. In 1737 the community had finally to declare bankruptcy.