This book contains the edition of two excavations conducted in Comacchio between 2006 and 2009. The excavation edition and the study of the materials are accompanied by studies on the environment, trade and economy, construction techniques, nutrition. , on funerary rituals, on ways of life: essentially they outline the profile of a maritime community between Late Antiquity and the modern era. One of the most important commercial hubs of the Adriatic and Mediterranean high Middle Ages, antagonist of Venice, told for the first time through archeology. The excavation of Piazza XX Settembre, which sees the scientific co-direction of the Superintendency and the Ca 'Foscari University, thanks to the support of the Municipality, represents a formidable opportunity for research, provided by the application of preventive archeology. The articulated research project of Ca 'Foscari, aimed at reconstructing the dynamics underlying the birth of the settlement, opens the view to the North Adriatic and European context. The 2008 and 2009 investigations in Villaggio San Francesco and the 2010 surveys north of the Ex Zuccherificio allow us to further specify the physiognomy and function of the "pile dwellings" found since 1924 and subject to subsequent investigations, clearly delineating the existence of a extended port district to the west of Comacchio, highlighting piers, warehouses and homes, in their evolutionary phases.