This study aims to identify the way in which the Roman historian Livy structured the narrative of the third book of his History, considering a dichotomy between moderation and immoderation as the main theme around which individual actions and events reported in this section of Livy's monumental work are centered. Through analysis of the most relevant episodes in book 3, it will be demonstrated how the historian established an original and well-elaborated link among virtue, personality and political power within the narrative framework, which is related to Livy's thoughts about Roman history and history-writing, as seen in Livy's preface and in book 3.