The revocation of the Edict of Nantes by Louis XIVin October 1685, made Protestant worship in France illegal. This remained the case until they received limited toleration during the French Revolution. Following his rise to power, Napoleon Bonaparte promulgated the law of 18 Germinal an X on 8th April 1802, which granted full religious tolerance to French Protestants.
In the 121 articles of this law, also known as les Articles Organiques (the Organic Articles), Bonaparte sought to regulate public worship in France and to limit the divisive forces it could unleash. 44 of the articles applied to the Protestants. They received the freedom to worship, but they were to have no national synod, which may have created a state within the state. Rather, the law established regional church organisations known as consistoires.
The remaining 77 articles set down the relationship between the French state and the Catholic church. Pope Pius VII protested against the effective nationalisation of the Gallican Church and its subordination to state regulation. Nevertheless, Bonaparte’s power meant that the pontiff had little choice but to sign the document.
You can read more about the Organic Articles in an article on the Catholic Encyclopedia site.