 The first hamlets of Adria were settled by the Veneti; also the settlement of Frattesina, near modern Fratta Polesine, was active by this river during these centuries.During the 9th or 8th century BC the main stream of the Po river changed, due to the so-called "breach at Sermide", and followed a channel more to the south, the Spina river.The Etruscans dug canals in order to drain the "Adrian swamps" (i.e.