 The Corpus forms the basis of Latin jurisprudence ( including ecclesiastical Canon Law ) and , for historians , provides a valuable insight into the concerns and activities of the later Roman Empire . As a collection it gathers together the many sources in which the leges ( laws ) and the other rules were expressed or published : proper laws , senatorial consults ( senatusconsulta ) , imperial decrees , case law , and jurists ' opinions and interpretations ( responsa prudentum ) . Tribonian 's code ensured the survival of Roman law . It formed the basis of later Byzantine law , as expressed in the Basilika of Basil I and Leo VI the Wise . The only western province where the Justinianic code was introduced was Italy ( after the conquest by the so @-@ called Pragmatic Sanction of 554 ) , from where it was to pass to Western Europe in the 12th century and become the basis of much European law code . It eventually passed to Eastern Europe where it appeared in Slavic editions , and it also passed on to Russia . It remains influential to this day . 
