This volume brings together the Proceedings of the seminar held on 29 and 30 October 2015 at the Department of Humanities of Ca 'Foscari University of Venice. The title of the book, which is the same as the seminar, refers to the age of consolidation of Venice, that had been identified by the promoters of the initiative as the 9th and 10th centuries. All the papers in the volume, therefore, consider a Venetian reality as already formed, even in its early days; a reality, or rather a social, economic and political community which, at this moment in time, reinforces its urban aspect, and creates the basis for the growth that will characterize its history after the tenth century. The book collects twelve papers of archaeological, historical, epigraphic and historical-artistic subject.