Before the Reformation in16th century, it became a legal system prevailing in the whole of western Europe. Church law absorbed some contents of Roman law represented by Justinian Code, and gradually formed its own principles and systems. In the early Middle Ages, Christian priests were the only intellectual class in society at that time. Priests participated in legislation and served as judges, and priests who were proficient in Roman law served as legal advisers to the Germanic kingdom. Therefore, many principles, terms and concepts of Roman law were absorbed in the formulation of church regulations; Roman law norms are widely used in the trial of secular civil cases. The creditor's rights law and family law in church law inherit many factors of Roman law. Therefore, some contents of Roman law are important sources of church law, and the compilation of the Complete Book of Church Law is based on the Complete Book of National Law of Roman law. The church often uses Roman jurists to annotate and comment on the law, and some even say that the church legal system is a descendant of Kunqu opera in Justinian Roman law. Both western and eastern church laws are deeply influenced by Roman law and accept a lot of concepts and rules of Roman law in classical and post-classical periods. So that "in the culture dominated by clans in western Europe, the church is regarded as the successor of Roman law." In the 8th century, ripley's "Anne Frank Code" and ripley's "An Law" contained such a passage: ecclesia vivitromano, which means that the church lives by Roman law. In an era when everyone regards their own national law as personal law, that is to say, people must judge according to this law no matter where they go and in what context, so in this sense, the personal law of the church is Roman law. "

Fourth, the influence of Roman law on later laws. Roman law not only had a great influence on Germanic law and canon law at that time, but also had a far-reaching influence on many European countries in various ways. When discussing the influence of Roman law, some scholars said: "Few countries can completely keep out of contact with it. Its influence ranges from Britain's absorption of some Roman legal thoughts to Germany's adoption of many specific rules and a set of Roman law concepts. " The adoption of Roman law varies from country to country. Italy, Spain, France and Germany are larger in scale and degree, while Britain and Yugoslavia are smaller in scale and degree. Since the beginning of19th century, the influence of Roman law has expanded rapidly. For example, the French Civil Code of 1804 is based on the path of law, which fully absorbs and continues Roman-Roman law and becomes a "code of typical bourgeois society"; The influence of Roman law in France can be divided into two parts: north and south. The south is dominated by written law, which is strongly influenced by Roman law, but it also contains more Germanic law factors. Although the northern part is dominated by customary law, it does not completely exclude Roman law. Due to the incompleteness of customary law, judicial personnel turn to Roman law in practice. German Civil Code 1900 is more influenced by the collection of theories, which is called "collection of modern theories". Germany's absorption of foreign Roman law began in the 4th century A.D./KLOC-0. Germany's inheritance of Roman law is very profound, whether it is the extensive inheritance of Roman legal theory or the scientific systematization of legal thought. The inheritance of Roman law in Germany is from the academic field to the practical field, from simple to complex. The contract principle, testament system and trust rules in English common law all come from Roman law, so Britain's acceptance of Roman law mainly comes from principles and spirit, not conceptual terms. Under the impact of the wave of Roman law in continental Europe, English law is bound to be greatly impacted. In the process of forming the common law foundation, Roman law did have an important influence on the formation of British legal theory. 12 century, there is no fundamental difference between England and other countries in continental Europe. Laws are based on customary law, and the laws in different regions are different. The minister in charge of equity procedure in England often has the status of a priest, and the cases under the jurisdiction of the minister in charge of seals are tried according to the concept of conscience and justice. Because the equity court of English law pays attention to the principle of fairness in reality, it is exactly the same as the concept of judge justice in Roman law with the help of civil law, and all roads lead to the same goal. Therefore, the equity law in England was also influenced by Roman law. Nevertheless, England did not embark on the road of inheriting Roman law in an all-round way, but applied the legal concepts and clauses of Roman law to discuss its actual legal problems. They just absorbed the spirit of Roman law and adopted the principles of departmental Roman law. The inheritance of Roman law in Europe is a multifaceted phenomenon, and other countries, such as Belgium, Spain, Finland, Netherlands, Poland, Switzerland, Japan and old China, have also been influenced by Roman law to varying degrees. In this process, no region or country consciously accepted all Roman laws. This inheritance is a process that each country or region adopts Roman law according to its own needs under the background of the times, and integrates these extracted Roman laws with the original laws of the country or region. Therefore, different demands lead to different content and degree of inheritance, and also lead to different resistance in different countries. Finally, it led to the emergence and differentiation of the two legal systems in the world and promoted the birth of modern ideas and systems. In a word, Roman law is a legal system that has made great contributions to the world legal civilization. It not only influenced and acted on slave society and feudal society, but also promoted the formation of new capitalist economy. Even today, Roman law still has different degrees of influence on the legal system of modern bourgeois countries.