PORTO TORRES (anc. Turris Libisonis, q.v.)  , a seaport on the north coast of Sardinia, 122 M . N.W. of Sassari by rail . Pop . (1901), 3762 (town); 4225 (commune) . It is only ro ft. above sea-level, and is malarious, but is a seaport of some importance, having regular steam communication with Ajaccio, Leghorn and Cagliari, and with the north and west coasts of Sardinia . The church of S . Gavino, formerly the cathedral, probably dates from the iith century . It is a Romanesque basilica with a nave and two aisles, divided by ancient columns; at each end of the nave is an apse . It has a 14th-century portal and two smaller doors at the sides added later in the Aragonese style . See D . Scano, Storia.dell' ark in Sardegna dal XI. al XIV. secolo (Cagliari–Sassari, 1907), 91 sqq . To the N.N.W. is the island of Asniara, the principal quarantine station of Italy .

Porto Torres was the seat of the giudici of the north-west portion of the island (the district was called Torres or Logudoro) ; it was plundered by the Genoese in 1166, but remained the seat of the giudici until 1272, when it was divided between various Genoese families, the Doria, Malaspina, &c., and the giudici of Arborea . It was also the seat of a bishopric until 1441, when the see was transferred to Sassari, Porto Torres being practically deserted, owing to its unhealthiness . It did not become an independent commune again until 1842 .