A Pentecontore at Ostia, in 220 BC. JC.. Note the slender (Greek) lines of these light galleys, still serving as scouts before being supplanted by the liburnes.
The Penteconter is one of the oldest galleys deployed by the Romans on their own (hitherto they appealed to the Greek ships of the colonies of the south of the boot or Syracuse). Very ancient, since it dates back to the Trojan era (1500 BC), the Pentecontore was "Romanized" when the latter built or commissioned it on their own account. They were not stowed, with their partial decks (only at the front and rear), and the absence of throwing weapons, raven or other standard equipment of triremes, quadrirèmes, and quinquères, among the units "Offensive", but as ships of liaison, carriers of dispatch, rapid transport, or scout, assigned role in the navies posterior to the frigate, the pinnace, or to the cruiser.
The Roman Pentecontore was ranked among the "monéris" (moners, ships with a single row of oars), constituting the top of the "naval dust" of the time. With 50 rowers in a single row, protected by a wooden bulwark, and only a few infantrymen (12 legionnaires at best), the Pentecontore Romaine (the name was not "romanized"), was supplanted around 50 BC. JC. By the new Liburnes inspired by Illyrian pirates, smaller, more manageable and quick.