Byzantine law was essentially a continuation of Roman law with increased Orthodox Christian and Hellenistic influence. Most sources define Byzantine law as the Roman legal traditions starting after the reign of Justinian I in the 6th century and ending with the Fall of Constantinople in the 15th century. Although future Byzantine codes and constitutions derived largely from Justinian's Corpus Juris Civilis, their main objectives were idealistic and ceremonial rather than practical. Following Hellenistic and Near-Eastern political systems, legislations were tools to idealize and display the sacred role and responsibility of the emperor as the holy monarch chosen by God and the incarnation of law "nómos émpsychos", thus having philosophical and religious purposes that idealized perfect Byzantine kingship.

Though during and after the European Renaissance Western legal practices were heavily influenced by Justinian's Code (the Corpus Juris Civilis) and Roman law during classical times, Byzantine law nevertheless had substantial influence on Western traditions during the Middle Ages and after.

The most important work of Byzantine law was the Ecloga, issued by Leo III, the first major Roman-Byzantine legal code issued in Greek rather than Latin. Soon after the Farmer's Law was established regulating legal standards outside the cities. While the Ecloga was influential throughout the Mediterranean (and Europe) because of the importance of Constantinople as a trading center, the Farmer's Law was a seminal influence on Slavic legal traditions including those of Russia.

Byzantium inherited most of its political institutions from the late Roman period. Similarly, Roman law constituted the basis for the Byzantine legal system. For many centuries, the two great codifications carried out by Theodosius II and Justinian respectively, were the cornerstones of Byzantine legislation. Of course, over the years these Roman codes were adjusted to the current circumstances and then replaced by new codifications, written in Greek. However, the influence of Roman law persisted, and it is obvious in codifications, such as Basilika, which was based on Corpus Juris Civilis. In the 11th century, Michael Psellos prides himself for being acquainted with the Roman legal legacy ("Ἰταλῶν σοφία").

Although Byzantine law structure had largely a Roman constitutional body, the main difference of Byzantine law from its Roman counterpart was both in its application and interpretation which were subject and applied under different Hellenistic and Orthodox principles shared between the Byzantine academic currículum, developing a legal system that encouraged different interpretations of law according to philanthropy and evergetia rather than the application of justice itself, acting for the well-being and benefit of the population rather than for the correct structuring of society.

The various philanthropics values of different classical philosophies intermixed with jurisprudence were already a fixed custom in the different code books and constitutions of the Ancient Hellenistic and Near-eastern kingdoms which practiced jurisprudence like a branch of literature and philosophy rather than a science of its own as pioneered by the Roman approach. Said customs and constitutions instituted greater influence at Christianity's arrival, being included in Justinian's novels which dictated that the law should be interpreted on the basis of philanthropy and piety as the emperors of the Macedonian dynasty had acted against the constant abuses and evasions of the dynatoi by imposing the allelengyon or through the different establishment of humanitarian and monastic institutions across the empire.

By the time the Ecloga and the Basilika were being codified, a further increase in Hellenistic and Christian values were also put into practice, all death penalties were replaced with amputations and severe economic sanctions while making further clarifications and references to the different Orthodox and Hellenistic concepts like that the judge should not only be the law incarnate, but also had to interpret it on the basis of "philanthrōpía" and "evergetikós". Thus, verdicts were applied being directly influenced by the different values, ethics and philosophies of their Orthodox social environment and not by the legal provisions of the code books, resulting in the misapplication and misinterpretation of a theoretically and strictly non-malleable Roman law.

In the absence of capable and efficient legal systems and the eclectic Byzantine approach to jurisprudence, most judges and legal processes across the empire were carried through simplified and vernacular laws such as The Farmers' Law, The Sea Laws, The Military Laws or the lesser known Mosaic Law, the different Orthodox and Hellenistic values or orally through the efficient and persuasive use of rhetoric rather than the legal provisions themselves, without Roman law seeing any proper fully systematized or continuing application whatsoever.