galia sottil. The dromon and the galea The primary warship of the Byzantine navy until the 12th century was the dromon and other similar ship types. Considered an evolution of the Roman liburnian, the term first appeared in the late 5th century, and was commonly used for a specific kind of war-galley by the 6th century. The term dromōn (literally "runner") itself comes from the Greek root drom-(áō), "to run", and 6th-century authors like Procopius are explicit in their references to the speed of these vessels. During the next few centuries, as the naval struggle with the Arabs intensified, heavier versions with two or possibly even three banks of oars evolved. The accepted view is that the main developments which differentiated the early dromons from the liburnians, and that henceforth characterized Mediterranean galleys, were the adoption of a full deck, the abandonment of rams on the bow in favor of an above-water spur, and the gradual introduction of lateen sails. The exact reasons for the abandonment of the ram are unclear. Depictions of upward-pointing beaks in the 4th-century Vatican Vergil manuscript may well illustrate that the ram had already been replaced by a spur in late Roman galleys. One possibility is that the change occurred because of the gradual evolution of the ancient shell-first construction method, against which rams had been designed, into the skeleton-first method, which produced a stronger and more flexible hull, less susceptible to ram attacks. At least by the early 7th century, the ram's original function had been forgotten. The dromons that Procopius described were single-banked ships of probably 25 oars per side. Unlike ancient vessels, which used an outrigger, these extended directly from the hull. In the later bireme dromons of the 9th and 10th centuries, the two oar banks were divided by the deck, with the first oar bank was situated below, whilst the second oar bank was situated above deck; these rowers were expected to fight alongside the marines in boarding operations. The overall length of these ships was probably about 32 meters. The stern (prymnē) had a tent that covered the captain's berth; the prow featured an elevated forecastle that acted as a fighting platform and could house one or more siphons for the discharge of Greek fire; and on the largest dromons, there were wooden castles on either side between the masts, providing archers with elevated firing platforms. The bow spur