Middle Ages in northern Britain. Medieval and early modern galleys used a different terminology from their ancient predecessors. Names were based on the changing designs that evolved after the ancient rowing schemes were forgotten. Among the most important is the Byzantine dromon, the predecessor to the Italian galea sottila. This was the first step toward the final form of the Mediterranean war galley. As galleys became an integral part of an advanced, early modern system of warfare and state administration, they were divided into a number of ranked grades based on the size of the vessel and the number of its crew. The most basic types were the following: large commander "lantern galleys", half-galleys, galiots, fustas, brigantines, and fregatas. Naval historian Jan Glete has described as a sort of predecessor of the later rating system of the Royal Navy and other sailing fleets in Northern Europe. The French navy and the Royal Navy built a series of "galley frigates" from c. 1670–1690 that were small two-decked sailing cruisers with a set of oarports on the lower deck. The three British galley frigates also had distinctive names – James Galley, Charles Galley, and Mary Galley. In the late 18th century, the term "galley" was in some contexts used to describe minor oared gun-armed vessels which did not fit into the category of the classic Mediterranean type. In North America, during American Revolutionary War and other wars with France and Britain, the early US Navy and other navies built vessels that were called "galleys" or "row galleys", though they were actually brigantines or Baltic gunboats. This type of description was more a characterization of their military role, and was in part due to technicalities in administration and naval financing. In the latter part of the 19th century, the Royal Navy term for the gig (a ship's boat optimised for propulsion by oar) reserved for the captain's use was, very strictly, "galley" – even though it was issued to the ship by the navy dockyard as a gig. History Among the earliest known watercraft were canoes made from hollowed-out logs, the earliest ancestors of galleys. Their narrow hulls required them to be paddled in a fixed sitting position facing forward, a less efficient form of propulsion than rowing with proper oars, facing backward. Seagoing paddled craft have been attested by finds of terracotta sculptures and lead models in the region of the Aegean