From the 4th century BC on, new types of oared warships appeared in the Mediterranean Sea, superseding the trireme and transforming naval warfare. Ships became increasingly large and heavy, including some of the largest wooden ships hitherto constructed. These developments were spearheaded in the Hellenistic Near East, but also to a large extent shared by the naval powers of the Western Mediterranean, specifically Carthage and the Roman Republic. While the wealthy successor kingdoms in the East built huge warships ("polyremes"), Carthage and Rome, in the intense naval antagonism during the Punic Wars, relied mostly on medium-sized vessels. At the same time, smaller naval powers employed an array of small and fast craft, which were also used by the ubiquitous pirates. Following the establishment of complete Roman hegemony in the Mediterranean after the Battle of Actium, the nascent Roman Empire faced no major naval threats. In the 1st century AD, the larger warships were retained only as flagships and were gradually supplanted by the light liburnians until, by Late Antiquity, the knowledge of their construction had been lost.

A galley was a type of ship which relied mostly on oars for propulsion that was used for warfare, trade, and piracy mostly in the seas surrounding Europe. It developed in the Mediterranean world during antiquity and continued to exist in various forms until the early 19th century. It typically had a long, slender hull, shallow draft, and often a low freeboard. Most types of galleys also had sails that could be used in favourable winds, but they relied primarily on oars to move independently of winds and currents. The term "galley" originated from a Greek term for a small type of galley and came in use in English from about 1300. It has occasionally been used for unrelated vessels with similar military functions as galley but which were not Mediterranean in origin, such as medieval Scandinavian longships, 16th-century Acehnese ghalis and 18th-century North American gunboats.