Justinian I (c.482-565)

Eastern Roman emperor
Justinian I is famous for reuniting the eastern and western halves of the Roman Empire in the 6th century, albeit temporarily, but more importantly he implemented one of the greatest and enduring codifications of law in history.
In AD 527 Justinian succeeded his uncle Emperor Justin I to become ruler of the Eastern Roman (Byzantine) Empire, and dedicated himself to restoring the boundaries of the old empire. With able generals, such as Belisarius and Narses, and under the guidance of his powerful and cunning wife, Theodora, Justinian wrested North Africa from the Vandals and Italy from the Goths, finally reuniting the eastern and western empires. He also successfully negotiated a truce with Persia in order to protect the eastern borders of the empire.
Within the vast empire, and over a span of ten years, he codified and drastically reformed the entire legal system by introducing the "Corpus Juris Civilis" (Body of Civil Law). The Justinian Code, as it became known, served as the basis for much of European law for many centuries.