Impacts of Ship-Building Advancements on the Medieval World

Early Middle Ages

During the EarlyMiddle Ages, Knar one of the most popular ships. Similar to longship,Knar was a type of cargo vessel used by the Vikings. It differed from the longship in that it was larger and relied almost entirely on its square-rigged sail for propulsion [2]. Knar was built for long voyages since it could take more cargo and be operated be smaller crew. Commercially, it was used to transport goods like walrus ivory, wool,timber, wheat, furs, and pelts [3]. It was also used in the military to supply food, drink, weapons, and armors to warriors across the Baltic and the Mediterranean.


High Middle Ages

Cogs first appeared in the 10th century and was widely used from around the 12th century. Current archaeological evidence points to the Western Jutland as the possible origin of this ship [6]. For centuries, Limfijord in northern Jutland provided stable passages for travelers between the North Sea and the Baltic. However,due to unusual geographical conditions and strong currents, the shallow sea was constantly filled with sand and became completely blocked by the 12th century [3]. As a result, large ships that could not be pulled across the sandbar had to circumnavigate the danger Cape Skagen to get to the Baltic. As a result, modifications were made from the knar to allow for more dangerous passages.

Cogs were characterized by a flat bottom at midships but shifted to overlapped strakes near the sterns. The flat bottom allows for easier settlement, which also makes loading and unloading faster for the crew. Fore and stern castles and high sides were added for defense against pirates. Additionally, cogs were heavily used during the Battle of Sluys [5].


Another type of ship used during the High Middle Ages was the hulk. The hulk was first recorded in the 10th century. Similar to cogs, hulks were clinker-built and had flat bottoms [4]. However, they are strongly curved upwards at stem and stern. Hulks were particularly associated with the Baltic and the Hanseatic League, a commercial and defensive confederation of merchant guilds and market towns in Northwestern and Central Europe [6]. Due to its widespread commercial use by the Hanseatic League, scholars agree that the hulk was predominantly a cargo vessel.


Late Middle Ages

Caravel was developed in the 14th century by the Portuguese to explore along the West African coast. The lateen sails allowed it to travel against the wind, especially in the East Atlantic [2]. Being smaller and having a shallow keel, the caravel could sail upriver in shallow coastal waters. It was highly maneuverable and could sail much nearer the shore, allowing for more convenient loading and unloading of goods. However, one significant drawback of early caravel was its limited capacity for cargo and crew. For the commercial purposes, caravels were later replaced by larger carracks,which were more profitable for trading [5]. Carracks were usually three or four-masted. Because of its larger size relative to that of caravels, carracks were large enough to be stable in heavy sea. As a result, they were often used for trade from the Mediterranean to the Baltic.


Maritime Warfare

In the early Medieval period, ships in the context of warfare were primarily used for transporting goods and troops. During the High and Late Middle Ages, naval warfare became similar to that of the late Roman Empire. Fleets would exchange missile fires and then try to board the opponent’s deck. This mode of naval warfare remained basically the same into early modern period.

  • Battle of Nicomedia Bay (718) – Arab Siege of Constantinople; naval battles fought just outside Constantinople’s harbor; involved 760 vessels 
  • Battle of Sluys (1340) – Opening battle of the Hundreds Years War; involved at least 200 ships;
  • Battle of Zonchio (1499) – Venice went to war against the Ottoman Empire; involved dozens of galleys and warships against a Turkish fleet
Battle of Nicomedia Bay

Trade in the Mediterranean

In the centuries after the fall of Rome, trade in the Mediterranean died down gradually. This is due to the fact that oar knars and galleys sometimes required a crew of over 200 men. In addition to the limited amount of cargoes that could be carried and the tough ride in the open sea, merchants were discouraged to conduct long passages.However, new ship building techniques allowed for longer voyages,urging traders to travel further. Along with the introduction of compass from China and other naval tools such as the astrolabe and the quadrant, traders conducted and explored further areas during the 13th century. By the early 1300’s, cargo ships from Genoa and Venice were taking metals, silks, and other luxuries from the eastern Mediterranean to England and Flanders (Belgium). German and Dutch ships took iron, copper, and lead south to the Mediterranean and brought back wine, oil, and salt.

Trade Routes during Late Middle Ages


[1] Hiroshi, Niki. The city of Osaka in the medieval period: Religion and the transportation of goods in the Uemachi Plateau. Culture and Society 2012.

[2] Hyland, Ann. The Medieval Warhorse: From Byzantium to the Crusades. London: Grange Books 1994.

[3] Leighton, Albert. Transport and communication in early medieval Europe, A.D. 500-1100. David & Charles 2007. P.214-257

[4] Noe, Ilano. A study of population density of ancient, medieval and modern cities in relation to transportation. MIT 1961.

[5] Prestwich, Michael. “Armies and Warfare in the Middle Ages”. New Haven: Yale University Press 1996.

[6] Scandurro, Enrico. “The Maritime Republics: Medieval and Renaissance ships in Italy”. London: Thames & Hudson 1972.