Today, civil law applies in the Republic of South Africa, Namibia, Lesotho, Swaziland, Botswana and Zimbabwe. In Sri Lanka it is present to a lesser extent, and in Guyana it was largely replaced by English common law from 1917. Reservations are made to indigenous laws and customs, to the extent that they are recognized; Moreover, the common law of these countries has departed in many respects from its original type. Only England and the Nordic countries did not participate in the full reception of Roman law. One reason for this is that at the time of the rediscovery of Roman law, the English legal system was more developed than its continental counterparts. As a result, the practical benefits of Roman law were less obvious to English practitioners than to continental jurists. As a result, the English common law system developed alongside Roman civil law, its practitioners being trained at the Inns of Court in London, rather than obtaining degrees in canon or civil law at the universities of Oxford or Cambridge. Elements of Roman canon law were present in England in ecclesiastical courts and, less directly, through the development of the judicial system. In addition, some concepts of Roman law have found their way into the common law. Especially in the early 19th century, English jurists and judges were ready to adopt the rules and ideas of continental jurists and directly Roman law. As lawyers know, the legal systems of countries around the world generally fall into one of two main categories: common law systems and civil law systems. There are about 150 countries that can be described primarily as civil law systems, while there are about 80 common law countries.
The Italian Civil Code of 1942 replaced the original one of 1865 and introduced Germanic elements due to the geopolitical alliances of the time.  The Italian approach has been imitated by other countries such as Portugal (1966), the Netherlands (1992), Lithuania (2000), Brazil (2002) and Argentina (2014). Most of them have innovations introduced by Italian legislation, including the unification of the Civil and Commercial Code.  Here is a complete list of countries that base their legal systems on codified civil law: In the Western world, only England, its colonies and the Scandinavian countries developed legal systems different from those of ancient Rome. But even these countries owe a debt of gratitude to the Romans for creating many legal concepts, principles, and rights that govern the lives of their citizens today. To give readers a starting point, here are some examples of countries that primarily practice common law or civil law. Roman civil law is practiced in Latin American and continental Western European countries such as Spain, China, Japan, Germany, most African countries, all South American countries (except Guyana). In Latin America, this legal system is rooted in the legal systems of its colonial masters in Spain and, in the case of Brazil, Portugal. Lawyers have also produced all sorts of legal sanctions. Around 130 AD, the jurist Salvius Iulianus drafted a standard form of praetorian edict, which was used by all praetors from that time on.
This edict contained detailed descriptions of all cases in which the praetor authorized a claim and in which he granted a defense. The standard edict thus functioned as a complete legal code, even if it did not formally have the force of law. He stressed the prerequisites for a successful trial. The edict thus became the basis for many legal commentaries by later classical jurists such as Paul and Ulpian. The new legal concepts and institutions developed by preclassical and classical jurists are too numerous to mention here. Here are a few examples: Lawyers have performed a variety of roles: they have provided legal advice at the request of private parties. They advised judges in charge of the administration of justice, especially praetors. They assisted the praetors in drafting their edicts in which they publicly announced, at the beginning of their mandate, how they would exercise their functions and the formulas according to which certain procedures were conducted. Some lawyers have also held high judicial and administrative positions themselves. Today, Roman law is no longer applied in legal practice, although the legal systems of some countries such as South Africa and San Marino are still based on the former municipality of ius. But even when legal practice is based on a code, many rules derived from Roman law apply: no code has completely broken with Roman tradition.
On the contrary, the provisions of Roman law have been inserted into a more coherent system and expressed in the national language. For this reason, knowledge of Roman law is essential to understanding today`s legal systems. Thus, Roman law is often still a compulsory subject for law students in civil law jurisdictions. In this context, the Moot Court of International Law has been developed annually to better educate students and to network with each other internationally.    The sources of English common law are Constitution (not in the UK), Legislation – Statutes and Subsidiary Legislation, Judicial Precedent – Common Law and Equity, Custom, Convention and International Law. Common law countries do not always follow a constitution or a code of law.