Quebec’s Civil Code is actually its second one. The Civil Code of Quebec came into force in 1994. The first one was the Civil Code of Lower Canada, adopted for Canada East or Lower Canada of the united Province of Canada in 1866 the year before Confederation.
It was based on the principles of the French Civil Code (the “Napoleonic Code”), but the drafters looked at a number of other codifications, including the Louisiana Civil Code (also based on the same legal matter as the Napoleonic Code was based on), and even a few rules derived from common law.
A reason for this was that Lower Canada, a remnant of the former French colony of New France, used the Coutume de Paris (Parisian customary law used in Northern France before the Napoleonic Code came into force) instead of English common law for its private law and by this time, as the Coutume de Paris was no longer in force in France, new legal commentaries were not being published about it it. So in order to preserve the civil law system, but bring it up to date, it was decided to adopt a civil code of the same type as was in force in France.
The term “Roman law” is often used in common parlance to describe the systems of civil law jurisdictions; however, modern civil codes are significantly evolved from the laws of Ancient Rome, though their traditions certainly have a lineage going back to Roman codification (the Twelve Tablets, Justinian’s Code) and legal principles.