The Romans developed a sophisticated body of law over one thousand years. The law was consulted and used in medieval and modern Europe, and from Europe it was exported around the world. Many modern legal systems are based, or partly indebted to, Roman law. The Roman legal tradition endured, even as specific rules fell away. The success of the legal tradition is due to the quality of the legal materials that the Romans produced. Roman office holders were eager to extend new rights to the public, and a professional body of lawyers were skilful in developing those rights and bringing them to a high degree of precision. The Romans eventually produced a systematic framework for their law, and that framework is still reflected in many modern legal systems. The framework paired two diverse bodies of law, property and obligations, which together reflected a person’s economic affairs. The two bodies are unequal; far more rights are treated under obligations than property, and the law of obligations is, to a large extent, an accessory to the law of property. The central role of property in Roman private law indeed proved to be a hindrance in the modern era, when states sought to use Roman private law as a foundation for their own legal systems.