Short answers, pulled from the story.
Emperor Justinian commissioned the Corpus Juris Civilis in the 6th century AD. This compilation synthesized centuries of legal thought into a coherent system that established sophisticated models for contracts, family law, and wills. The framework survived in the Eastern Roman Empire until its final fall in the 15th century.
The Code of Hammurabi from ancient Babylon was primarily a list of wrongs and punishments. The Napoleonic Code of 1804 went far beyond simple lists to state the law in a coherent, comprehensive piece of legislation that introduced major reforms and started anew. It comprised three components: the law of persons, property law, and commercial law.
Civil law judges tend to give less weight to court decisions and there is no doctrine of stare decisis in the French civil law tradition. Courts lack authority to act if there is no statute, and the system holds case law secondary and subordinate to statutory law. While an increasing degree of precedent is creeping into civil law jurisprudence, the typical French-speaking supreme court decision remains short and concise.
Civil law is the world's most common legal system, practiced in about 150 countries across every continent. It is the primary legal system in Continental Europe, East Asia, Central Asia, the Middle East, Central and South America, and North Africa. Specific examples include Poland, Louisiana, Japan, South Korea, Switzerland, Brazil, Turkey, and many nations in Latin America and Africa.
The legal system of Japan, beginning in the Meiji Era, drew roughly 60% from the German civil code and 30% from the French civil code. It also incorporated 8% from Japanese customary law and 2% from English law. This hybrid approach demonstrates the flexibility of civil law in adapting to new influences while maintaining core principles.