The intention behind the Napoleonic Code was to reform the French legal system in accordance with the principles of the French Revolution. Before the Code, France did not have a single set of laws. The vestiges of feudalism were abolished, and the many different legal systems used in different parts of France were replaced by a single legal code.
Developing out of the various coutumes of France notably the Coutume de Paris this recodification process that had first started by Justinian in the Byzantine Empire with the establishment of codified roman law. The development of the Code was a fundamental change in the nature of the civil law legal system. The development of these codes made the law much clearer, they were different in each country, and thus destroyed the superficial legal unity of Continental Europe which had existed in the Middle Ages.
The term "Napoleonic code" is also used to refer to legal codes of other jurisdictions that are derived from the French Code Napoleon, especially the civil codes of Louisiana and Lower Canada which was later revised into the Civil Code of Québec.
See: Lettre de cachet