Comparison between on one hand the development of legal culture on the mainland, based on the recovery, scientific study, interpretation and adaptation to medieval needs of Justinian’s compilation as imperial common law, and the uninterest of the Venetial legal culture for Roman law. Analysis of the reasons: independence from the Western Empire; integration of the legal system through timely legislation and through the jurisprudence of Curia di Petizion; suspicion toward the possible lobbying by the class of Roman jurists. Ratio de lege Romana and Judicia a probis judicibus promulgata. Institution of the Council of Forty to relieve the overwork of the Major Council pro bono et proficuum Communis Veneciarum. Development of the city. Protection of individual interests against derobationes (robberies) by criminal bands abroad. Trade agreement with the Sultanate of Aleppo.