Abstract:The Theodosian Code of the Late Western Roman Empire，It is the unified legal system faced by the Germanic people during the Great Migration。Afterwards，The Germans have established national laws one after another，Broken this legal system，Started the process of diversified legal construction。With the stability and development of feudal economic and social life，Feudal law gradually formed in app bet365 download in the Middle Ages、Canon Law、The situation in which the three major legal systems of maritime law stand side by side。The revival of Roman law unifies these three legal systems from a legal perspective，Thus forming the "Trinity" pattern of Western European law in the Middle Ages。Overall，The legal construction of app bet365 download in the Middle Ages has experienced from unity to pluralism，The process of moving from diversity to new unity。This has important implications for re-understanding the legal civilization of medieval app bet365 download。

　　Keywords:Middle Ages app bet365 download Law Diversity and unity Social nature

　　Author Zhang Naihe，Professor, Institute of app bet365 download Civilization and School of History and Culture, Tianjin Normal University (Tianjin 300387)。