h e limited number of ships that medieval kingdoms and peoples were capable of amassing was particularly evident in the years directly following the Roman Empire’s demise. Moreover, the vessels of that period lacked the speed, storage capacity, and overall military ef ectiveness of those in the later Middle Ages. h e earlier ones were galleys much like those employed by the Greeks, Romans, Phoenicians, and other ancient Mediterranean peoples. h ey operated primarily by the power of men pulling long oars. h e single, small, square-shaped sail that such a ship carried could sometimes supplement the rowers. But it was incapable of powering the vessel for very long in most situations. A typical early medieval galley was about 100 feet (30 m) long and featured twenty-i ve oars on each side. In naval terminology, those oars are more often called “benches” in reference to the wooden seats on which the rowers sat. With one man to a bench, there were therefore i fty rowers. Some of the early galleys had two banks of benches, one situated above the other, in which case there were one hundred rowers. Such a vessel also had a few sailors to maintain and guide it and a small number of marines (naval i ghters). h e rowers were expected to i ght alongside the marines during a clash with an enemy. Because these ships were relatively small yet carried quite a few people, there was no room for large stores of food and other supplies. h is meant that they could not remain at sea for more than a few days at a time. For this reason, as well as the lack of ef ective navigation instruments, galleys usually stayed within sight of coastlines and made frequent stops. Closely related in many ways to the early Mediterranean galleys, although smaller, were the oared boats that plied the waters of the North Sea. Chief among these were Viking longships. One that was unearthed in modern times—called the Gokstad ship—appears to be typical of the average longship in most ways. It is 76 feet (23 m) long and has sixteen benches to a side, which means it had thirty-two oarsmen. Partly because the Normans were descendents of Vikings who had settled in France, the oared vessels that Duke William built to carry his army across the English Channel in 1066 were very similar to longships.