it brought them some decisive victories, it was discontinued because it tended to unbalance the quinqueremes in high seas; two Roman fleets are recorded to have been lost during storms in the First Punic War. During the Civil Wars, a number of technical innovations, which are attributed to Agrippa, took place: the harpax, a catapult-fired grappling hook, which was used to clamp onto an enemy ship, reel it in and board it, in a much more efficient way than with the old corvus, and the use of collapsible fighting towers placed one apiece bow and stern, which were used to provide the boarders with supporting fire. Fleets Principate period After the end of the civil wars, Augustus reduced and reorganized the Roman armed forces, including the navy. A large part of the fleet of Mark Antony was burned, and the rest was withdrawn to a new base at Forum Iulii (modern Fréjus), which remained operative until the reign of Claudius. However, the bulk of the fleet was soon subdivided into two praetorian fleets at Misenum and Ravenna, supplemented by a growing number of minor ones in the provinces, which were often created on an ad hoc basis for specific campaigns. This organizational structure was maintained almost unchanged until the 4th century. Praetorian fleets The two major fleets were stationed in Italy and acted as a central naval reserve, directly available to the Emperor (hence the designation "praetorian"). In the absence of any naval threat, their duties mostly involved patrolling and transport duties. These were not confined to the waters around Italy, but throughout the Mediterranean. There is epigraphic evidence for the presence of sailors of the two praetorian fleets at Piraeus and Syria. These two fleets were: The Classis Misenensis, established in 27 BC and based at Portus Julius. Later Classis praetoria Misenesis Pia Vindex. Detachments of the fleet served at secondary bases, such as Ostia, Puteoli, Centumcellae and other harbors. The Classis Ravennas, established in 27 BC and based at Ravenna. Later Classis praetoria Ravennatis Pia Vindex. Provincial fleets The various provincial fleets were smaller than the praetorian fleets and composed mostly of lighter vessels. Nevertheless, it was these fleets that saw action, in full campaigns or raids on the periphery of the Empire. The Classis Africana Commodiana Herculea, established by Commodus in 186 to secure the grain shipments (annona) from North Africa to Italy, after the model of