One of the great gifts of Rome was that of law. Roman law played a major role in the eventual emergence of the West. Of all the great inheritances of Roman civilization, none were more important to Western Civilization that the heritage of Roman law. And today the imprint of law is one of the primary forces that mark the Western world. Roman law developed for about a milenia. The earliest Roman law was secretly administered as the law of the privileged classes. Over time it became the destinctive basis of civilized life throughout the Empire. Roman jurisprudence evolved into a legal system based on natural-law theory as the fundamental test of the reasonableness of positive law. The first major step toward a sophisticated legal system was the law of the Twelve Tables (449 BC). The cilmination of Roman lrgal development was Emperor Justinian I's Corpus Juris Civilis of (about 530 AD). Roman law, as preserved in Justinian's codes continued to be practiced in the Eastern Roman or Byzantine Empire until its fall (1453). The classical tradition was lost for centuries after the fall of Rome to the Germanic invaders and Huns. The Eastern Empire did not fall to the Barbarians. Thus it was largely through the Eastern or Byzantine Empire that Roman legal practice was passed to continental Europe during the medieval era.