It was during the twenties of the 18th century that the first people to openly practice Judaism appeared in St. Petersburg.
Officially it was prohibited for them to dwell not only in the capital, but in Russia in general (edict of Catherine I of 1727). Lithuania, Byelorussia and the greater part of Ukraine did not belong to the Russian Empire in those days. However, for the sake of convenience, some Russian monarchs violated the laws they had signed themselves. That is why those Jews whose services were needed at the court could live in St. Petersburg.
Jews living in St. Petersburg in those days were mostly financiers, merchants, and physicians. Those people were quite well to do and employed servants. The servants were also usually Jewish, so there were practically always enough people for a minyan at home. And though in Petersburg there were no official synagogues nor prayer houses, the Jews could pray in their homes.
However, there were cases of persecution of people who practiced Judaism. The most illustrative example was "The Case of Proselytism", which was examined by the Senate in 1738.
The rule of Anna Ioannovna was marked by severe repression of the Jews. In 1740 she signed an edict of expulsion of the Jews from Little Russia "by virtue of the previous laws", meaning the Edict of Catherine I of 1727.
In Russia the Jews remained an unwanted element of the population. On December 2, 1742 Elizabeth by a special decree not only confirmed the notorious edict of Catherine I but also required expulsion of the Jews, together with their properties, from both Russian and Ukrainian cities, towns, and villages.
Typical of Elizabeth's attitude towards Jews was her response to a request by the Russian senate to cancel this deportation. Members of the Senate feared that the expulsion of the Jews would cause a break in established trade relations, as well as financial losses to the state. The Empress declared, "From the enemies of Christ, I don't want to have any profits".
Thus the Jews were expelled from the Russian Empire; that is why their presence in St. Petersburg during the reign of Elizabeth was quite insignificant and has hardly been researched.