to need in her first struggles for maritime supremacy with Carthage." The port of Cosa provides us with the earliest Roman harbor known thus far, the earliest commercial fishery, the earliest evidence for the use of tufo and pozzolana concrete in water, and many other revolutionary and innovative practices, as well as imparting key insights, through the material evidence at the fishery and the Sestius amphorae, about the trade of fish, garum, and wine in the ancient world. Cosa under the Empire Cosa appears to have been affected by an earthquake in 51, which occasioned the reconstruction of the republican Basilica as an Odeon under the supervision of Lucius Titinius Glaucus Lucretianus, who also worked on the Capitoline temple; however, as early as 80, Cosa seems to have been almost deserted. It was revived under the emperor Caracalla, during whose reign was built the portico around the forum, concealing two large granaries, while the odeon were restored, a Mithraeum was constructed in the basement of the Curia, and a sanctuary to Liber erected at the southeast end of the Forum. The new town did not last long, however, and by the 4th century only the sanctuary of Liber was periodically visited. In the early 6th century some occupation in the ruins is attested by pottery and the remains of a church have been found built onto the Basilica. Perhaps at the same time the Arx was occupied by a fortified farm, subsequently transformed into a small fortified outpost under Byzantine control. This was abandoned in the late 6th or early 7th century. It is possible that the intermittent nature of the occupation of the town was due to the fact that, already in the early Empire, malaria was hyperendemic on the coast of Tuscany. Middle Ages Cosa appears in some documents dating from the 11th century, although a 9th-century occupation is suggested by frescoes at the abbey of S. Anastasio alle Tre Fontane in Rome, recording the capture of the site by Charlemagne and Pope Leo III. However, no sign of occupation between the eighth and the tenth century has been recovered. By the end of the 10th century, a small cemetery was found next to a church built over a temple facing the forum. The town is recorded as Ansedoniam civitatem in a privilege of Pope Gregory VII (1073-1085). Occupation of the site began with a few sunken-floored buildings,