The Grand Sanhedrin did not originate the questions it answered. In 1806, responding to complaints from Alsace about Jewish moneylending and to his own interest in whether Jews could be assimilated as full French citizens, Napoleon convened an Assembly of Jewish Notables, a body of rabbis and lay leaders drawn from across France and northern Italy, and put twelve questions to it directly: whether Jewish law permitted polygamy, whether it recognised civil divorce, whether it permitted a Jew to marry a Christian, whether Jews regarded Frenchmen who were not Jewish as brothers or as strangers, whether French-born Jews considered France their country and its laws binding, and further questions bearing on usury and Jewish economic practice.
The Notables answered in ways designed to demonstrate compatibility with French citizenship, but Napoleon wanted the answers given a religious authority the lay-heavy Notables could not fully supply on their own. He therefore ordered a second, more explicitly religious body convened: a Grand Sanhedrin, named for and modelled on the ancient Jewish high court, seventy-one members strong, composed mostly of rabbis with a smaller number of lay members, drawing delegates from French territory and, by invitation, from Jewish communities in Germany, Italy and the Netherlands as well.
The body met in Paris in February and March 1807 and issued a formal doctrinal decision, framed in the language and form of rabbinic responsa, ratifying the Notables' answers as consistent with Jewish law rather than as a concession to it.