The juridical history of the Catholic Church is the history of Catholic canon law, the oldest permanently functioning legal system in the West.   Canon law has its origins much later than Roman law, but predates the development of modern European civil law traditions. The cultural exchange between secular (Roman/Barbarian) law and ecclesiastical (canonical) law gave rise to ius commune and strongly influenced civil and customary law. One of the most important legal systems developed in the Middle Ages was Islamic law and jurisprudence. A number of important legal institutions were developed by Islamic jurists during the classical period of Islamic law and jurisprudence. One such institution was hawala, an informal system of value transfer that had already been established in the 8th century. It is mentioned in Islamic jurisprudence in the nineteenth century. Hawala himself later influenced the development of the Aval in French civil law and the Avallo in Italian law.  All of these individuals may own property and hold it for their own property (house, clothing, etc.) or as a business or investment (office buildings, factories, stocks, savings accounts).
Only socialist systems have attempted to prevent this second function of property by forbidding individuals to own „the means of production.” The property in question may be tangible and is often referred to as immovable and movable (or, at common law, immovable and personal). Ownership can also be intangible, such as debts, copyrights and patents. If owners have full legal capacity, they can generally manage their property as they wish, subject to public policy rules (e.g. zoning by-laws). They can manage their assets during their lifetime or their will, although many systems ensure that a portion of the deceased`s assets go to close relatives. Private law defines who is considered to have legal capacity and deals with their legal capacity (for the protection of the very young or mentally ill). These natural persons may create other „artificial” legal entities such as associations, foundations and companies. A common method is to require a special majority in the legislature – two-thirds in Germany, three-fifths in France, with similar systems in India and other Commonwealth countries (and this was the case in the Soviet bloc). Another parliamentary alternative is to ask for a second vote (Italy, Denmark, Finland).
Finally, some systems divide the power of amendment between legislators and citizens by requiring a referendum either for certain types or methods of change (Denmark, France, Ireland) or for each (Japan). Although the length of constitutions varies considerably, most details are usually devoted to the legislative and executive branches and the relationship between them. Federal systems, of course, have bicameral legislation. But also many unitary systems, where the House of Commons is directly elected and the House of Lords is composed of those who can represent rural interests (France) or have particular competences (Ireland). In most countries (but not in the United States), the House of Commons can ultimately override the House of Lords. The first group includes countries whose „mixed” system is influenced by both civil and common law. The old uncodified civil law of Holland is the basis of the Roman-Dutch law of South Africa, Zambia, Namibia, Lesotho, Swaziland, Botswana and Sri Lanka; it is characterized by a rich legal literature dating back to Hugo Grotius (de Groot) in the 17th century. But their long contacts with Britain mean that their public law and legal proceedings owe much to the common law. Two common patterns are that of the presidential system and that of the parliamentary system.
The former merges ceremonial and political power into a single office, with its holder elected directly and completely separately from the legislature: it is therefore quite possible (and common in the United States) for the president of one party and a majority of the legislature to belong to another party. It separates the executive and legislative powers, so neither institution can dissolve the other: the president is impeached only for serious crimes in which the legislature acts as a court. The president appoints ministers for confirmation by the legislature, but there is no collective responsibility of cabinet. The president usually has veto power over laws, which can only be overridden by a special parliamentary majority. On the other hand, the decisive power of taxation lies with the legislator. The two main traditions of modern European law are the codified legal systems of most of continental Europe and the English tradition based on case law.  The African legal system is based on common law and civil law.  It was based on tribal customs and traditions before colonization adopted its original system.  People listened to their elders and used their elders as the people they could turn to in times of conflict. They did not keep written records because their laws were often passed orally. During colonization, African authorities developed a formal legal system called indigenous courts.  After colonialism, the main religions that remained remained Buddhism, Hinduism and Judaism.
One of the most complex concepts in U.S. jurisprudence is the extent to which the various sources of law in state and federal systems are interrelated. There is a complex set of rules that define relative priority between different sources of law and between state and federal systems. Second, the federal judicial system is based on a system of „jurisdiction,” that is, the geographical distribution of courts at certain levels. For example, while there is only one Supreme Court, the Court of Appeal is divided into 13 counties and there are 94 district courts. In addition, each state judicial system has its own „jurisdiction”. As already mentioned, the jurisdiction in which a case has been raised determines which judicial decisions constitute binding precedents. Roman law was strongly influenced by Greek doctrine.  It is the bridge to the modern legal world, in the centuries between the rise and fall of the Roman Empire.
 Roman law was highly procedural at the time of the Roman Republic and the Empire, and there was no professional legal class.  Instead, a layman, iudex, was chosen to judge. Precedents have not been reported, so any jurisdiction that has developed has been obscured and almost not recognized.  Each case should be redecided from state laws, reflecting the (theoretical) insignificance of judges` decisions for future cases in today`s civil justice systems. During the 6th century AD in the Eastern Roman Empire, Emperor Justinian codified and consolidated the laws that had existed in Rome, so that what remained was one-twentieth of the mass of legal texts of the past.  This has been called the Corpus Juris Civilis. As one legal historian wrote, „Justinian consciously looked back at the golden age of Roman law and sought to bring it back to the peak it had reached three centuries earlier.”  Most modern legal systems can be described as either the common law, civil law, or a mixture of both. A system of pure customary law is created by the judiciary, since the law derives from case law and not from the law.