Egypt, rowing vessels, especially galleys, were extensively used in naval warfare and trade in the Mediterranean from classical antiquity onward. Galleys had advantages over sailing ships: they were easier to maneuver, capable of short bursts of speed, and able to move independently of the wind. Ancient Greece During the classical age of oared galleys, the Greeks dominated the Mediterranean while the Athenians dominated the other Greeks. They used thousands of lower-class citizens to serve as rowers in the fleet. The Classical trireme used 170 rowers; later galleys included even larger crews. Trireme oarsmen used leather cushions to slide over their seats, which allowed them to use their leg strength as a modern oarsman does with a sliding seat. Galleys usually had masts and sails, but would lower them at the approach of combat. Greek fleets would even leave their sails and masts on shore (as being unnecessary weight) if possible. Northern Europe The use of oars in rowing instead of paddling came rather late to northern Europe, sometime between 500 BC-1 AD. This change might have been hastened by the Roman conquest of Northern Gaul. However, between 500 and 1100 AD, combined sailing and rowing vessels dominated trade and warfare in northern Europe in the time that has come to be known as the Viking Age. Galleys continued to be used in the Mediterranean until the advent of steam propulsion. Types of rowing systems In some localities, rear-facing systems prevail. In other localities, forward-facing systems prevail, especially in crowded areas such as in Venice, Italy and in Asian and Indonesian rivers and harbors. This is not strictly an "either-or", because in different situations it's useful to be able to row a boat facing either way. The current emphasis on the health aspects of rowing has resulted in some new mechanical systems being developed, some (such as the Rantilla rowing method) very different from the traditional rowing systems of the past. Rearward-facing systems This is probably the oldest system used in Europe and North America. A seated rower pulls on one or two oars, which lever the boat through the water. The pivot point of the oars (attached solidly to the boat) is the fulcrum or the oar-lock. The motive force is applied through the rower's feet. The traditional terminology, in a strict interpretation, varies between boats operating on salt water and in fresh water. "Rowing" at sea denotes each rower