All three parts, even the manual, had the force of law. Together, they should be the sole source of law; Any reference to any other source, including the original texts from which the codex and digesta had been taken, was prohibited. Nevertheless, Justinian was forced to enact other laws, which are now counted as the fourth part of the corpus, the Novellae Constitutiones. Unlike the rest of the Corpus, the news appeared in Greek, the common language of the Eastern Empire. Later, by mixing the old obsolete laws with the new laws of the Roman Empire, Emperor Justinian I effectively cleaned and updated Roman law, choosing only those rules that had real practical value of the time, leaving behind all outdated principles and assumptions. The first book of the so-called Corpus Juris Civilis is the Codex Constitutionum. It represents a selection of imperial constitutions that had some practical value or whose provisions were adapted to the circumstances of Justinian`s time. The second book or series of volumes consists of 50 other volumes that became known as Digesta or Pandectae. They contained a selection of jurists` writings and were called the Code of Law, and no other legal writing could be cited.
Around the same time, the Institutes of Justinian were published. It contained an overview of the elements of Roman law. The last book is known as the New Constitutions or Romans and consists of decrees issued by the emperor himself. The table also describes several laws dealing with theft. Despite this unpromising start, Justinian and Theodora will achieve impressive feats. One was to almost unite the Roman empires of East and West by conquering many barbarian kingdoms that had taken control of the western Mediterranean. The first Roman code was the Lex Duodecim Tabularum, which was followed much later by a second code, known as the Corpus Juris Civilis. Both codices helped establish a guideline for Rome and made it a dominant empire for centuries. The Twelve Tablets are no longer preserved: although they remained an important source during the Republic, they gradually became obsolete and ultimately had only historical interest.
 The original tablets may have been destroyed when the Gauls burned Rome under Brennus in 387 BC. Cicero claimed that he memorized them when he was a child at school, but that no one learned them anymore. What we have from them today are short excerpts and quotations from these laws in other authors, often in clearly updated language. They are written in archaic and laconic Latin (described as the verse of Saturn). Although it cannot be determined whether the quoted fragments accurately retain the original form, what is present gives insight into the grammar of early Latin. Some claim that the text was written as such so that plebeians could memorize the laws more easily, as literacy was not commonplace in early Rome. Roman republican scholars have written commentaries on the Twelve Tablets, such as L. Aelius Stilo, professor of Varron and Cicero.
Despite his ties to the former emperor, Justinian was something of a stranger among the aristocrats of Constantinople, and he appointed a number of people to important positions based more on energy and ability than on family relationships. This gave him a core of talented subordinates who were able to carry out his ambitious plans. But at the same time, he also won the enmity of the old aristocracy. An important division of Roman law became what is now known as jus scriptum (written law) and jus non scriptum (unwritten law). The term unwritten law was strictly related to customs, while written law represented literally all law based on written sources and evidence. There were different types of written laws, the first of which consisted of leges or decrees of one of the general assemblies of the Roman people. They were a source of law only during the Republic. With the founding of the empire in 31 BC. The function of the assemblies was reduced to the formal ratification of the emperor`s wishes.
The most important legia or laws were the Twelve Tablets, published in 451 BC. This was the first attempt by the Romans to create a code of law to prevent political class struggles. Little is known about the actual content of the twelve panels. Unfortunately, the authentic text of the codex has not been completely preserved to this day and only a few fragments have been preserved. However, these fragments clearly show that many important legal issues such as family law, tort and court proceedings have been addressed by the Code. Many of today`s laws in the world date back to the beginnings with the twelve tablets. « Jus eat ars boni et aqua » The law is the art of goodness and justice. This is how the Roman jurist Celsus defined law. This definition represents and embraces the desires of the Roman people and their will to create and implement laws, a desire that actually managed to completely transcend the limits of time and reach the modern world as we know it today. Roman law is the stable foundation on which modern legal culture as a whole has developed and evolved. The civil law system is based on late Roman law and its most distinctive feature – that its fundamental principles are codified in a system that serves as the main source of law.
This code took laws from as far away as Romulus and Remus and organized them in a way that was not confusing to understand for the average citizen. The Justinian Codex dealt extensively with religion, as it enforced laws against heresy, paganism, and Judaism. The Code of Justinian was also divided into two legal sections. There was public law to deal with government, and there was private law to deal with individuals (Justinian Code: Ancient Rome/Byzantine Empire). The Justinian Codex was important for two main reasons. First, he made the law really simple and organized for everyone to understand. The Justinian Code included a codification of Roman laws, a guide for judges, and an introduction to law and code for law students (Justinian Code: Ancient Rome/Byzantine Empire). The other great code that came from Rome was the Corpus Juris Civilis, also known as the Justinian Code. This code was completed in 534 AD (Justinian code: Ancient Rome/Byzantine Empire). With the Justinian Codex in the Middle Ages, a revival of the study of Roman law began. This new code became the new legal form in all civil courts of the Reich. Some of the main topics covered are civil procedure, debts, parents and children, inheritance, property, tort and marriage.
Examples of laws introduced by this code were that a deformed child should be killed and that marriage between patricians and plebeians was prohibited. All these campaigns cost considerable sums of money, and the empire`s resources were eroded by a series of serious conflicts with the Sassanids residing in the Middle East, who remained a powerful and warlike empire. Offences are laws that deal with disputes between citizens. One such situation is that of bodily injury, the reprisals for which can range from material damage to financial compensation to the injured party. This table also lists the legal consequences of property damage caused by animals and damage to crops by humans or animals. The sentence for grain theft is suspended as a victim for Ceres.  The Twelve Tablets are of great importance for three main reasons. First, the twelve tablets are the foundation of the Roman Republic (The Twelve Panels: Foundations of Roman Law). The original laws in Rome had been enacted only for the benefit of the patricians, and the plebeians wanted to change that.
In 494 BC. The plebeians threatened to secede from Rome, and the patricians were forced to take note and promulgate laws that applied to all citizens (The Twelve Tablets: Foundations of Roman Law). This section of the tables makes it illegal for anyone to define what a citizen of Rome is, except for the largest assembly or maximus comitatus. It also prohibits the execution of persons who have not been convicted, the bribery of judges and the extradition of a citizen to hostile powers.  The Corpus forms the basis of Latin jurisprudence (including canon law) and provides historians with valuable insight into the concerns and activities of the later Roman Empire. As a compendium, it brings together the many sources in which laws and other rules have been expressed or published (ordinary laws, senatorial consultations, imperial decrees, case law, and opinions and interpretations of jurists). It formed the basis of later Byzantine law, as expressed in the Basilica of Basil I and Leo VI.dem of the Magi. The only western province where the Justinian Codex was introduced was Italy, from where it was incorporated in the 12th century. It has become the basis of many European legal systems.