Historian Louise Adena wrote the following about Byzantium and its impact on the West:
“The Byzantine or Eastern Roman Empire with Constantinople at its heart was established at the beginning of the fourth century AD by the Roman Emperor Constantine (272-337AD). While it remained a major world cultural and commercial centre for over 1000 years, it has been only during the twentieth century that European historians have come to acknowledge its profound influence on Western Europe. Its enduring legacies are seen in European art and legal systems. It was also key to the widespread adoption of Christianity in Europe; it was the base for the spread of learning in Europe providing continuity between ancient Greek and Roman civilisations and into the European Renaissance.” [Bold emphasis is mine]
The Eastern Roman empire, suffused in Greek and Near Eastern language and culture, is certainly one of history's forgotten empires. Along with Western Church canon law, some remnants of Roman Law, Byzantium certainly helped shaped Western legal jurisprudence and its impact is still in evidence today. Under Emperor Justinian (482-565AD) the Eastern Roman empire compiled laws and legislation into one legal code - the ‘Codex Justinianus’. This codex compiled into one extant form, all of the state's laws which the citizens would be obliged to follow.
This idea whilst not entirely revolutionary, was profound. It introduced the legal concept of innocent-until-proven-guilty, which relied on proof, witnesses, a due process and common-sense. Justinian's codex is therefore one of the main planks of our modern legal system, equalizing all citizens before an impartial set of laws, and ostracizing the baleful influence of wealth and power over proper legal proceedings and decisions.