Short answers, pulled from the story.
Civil law originated in Western Europe with the Justinian Code emerging in the 6th century AD as a sophisticated model for contracts and family law. This legal text became the primary inspiration for civil law systems across Europe after Roman law continued without interruption in the Eastern Roman Empire until its final fall in the 15th century.
France enacted the Napoleonic Code in 1804 under the direction of French emperor Napoleon. The code comprises three components covering persons, property, and commercial law while expressly forbidding French judges from pronouncing general principles of law in 1803.
Civil law is practiced in about 150 countries across the world today including nations in Continental Europe, East Asia, Central America, South America, North Africa, and Lusophone Africa. Specific examples include Indonesia, Japan, Kyrgyzstan, Turkey, Egypt, Angola, Cote d'Ivoire, Chile, Ecuador, El Salvador, Nicaragua, Honduras, Colombia, Panama, Venezuela, Cameroon, and Macau.
There is no doctrine of stare decisis in the French civil law tradition so civil law judges tend to give less weight to judicial precedent compared to common law systems. Civil law codes must be changed constantly because court precedents are not binding and courts lack authority to act if there is no statute present in the jurisdiction.
Napoleonic systems include France, Italy, the Netherlands, Spain, Chile, Belgium, Luxembourg, Portugal, Brazil, Mexico and most Arab world countries where Islamic law is not used. Germanistic systems cover Germany, Austria, Switzerland, Latvia, Estonia, Czech Republic, Russia, Lithuania, Croatia, Hungary, Serbia, Slovenia, Slovakia, Bosnia and Herzegovina, Greece, Ukraine, Turkey, Japan, South Korea, Taiwan and Thailand while Nordic jurisprudence includes Denmark, Finland, Iceland, Norway and Sweden together with Faroe Islands and Greenland.