Portogruaro was officially founded in 1140, when the
Archbishop of Concordia, Gervinus, gave a group of fishermen (Giovanni Venerio, Arpone, Bertaldo, Borigoio, Enrico Mosca, Giovanni Salimbene) the right to settle there and build a river port. A castle had existed on the site as early as the 10th century. In 1420, after centuries under
Patria del Friuli, was conquered by the
Republic of Venice. According to Bertolini the town's foundation could be coeval to the
Concordia Sagittaria's one. Under the Venetians the town retained some autonomy and was able to expand economically up until the economic decline of Venice from the 17th century onwards. Following the upheavals of the
Napoleonic Wars, Portogruaro was incorporated into the
Austrian Empire in 1815. Apart from a brief
uprising in 1848 Portogruaro remained under Austrian control until 1866 when it entered the newly unified
Kingdom of Italy. Since that time the population of Portogruaro has grown from under 10,000 to around 25,000. ==Main sights==