The British Isles were highly dependent on sea trade throughout the Middle Ages. Plantagenet incomes were heavily subsidised by tariffs levied on wool exports to Europe. At its peak, medieval England was exporting over 40,000 sacks of wool a year. Without this trade, Edward I, Edward III and Henry V would not have been able to finance their wars. And, of course, all this trade was conducted by sea.
But sea trade was not without its hazards. Storms might delay your journey, force you off course, or even wreck your ship. And, throughout the Middle Ages, piracy was a very real and often deadly threat. But, despite the dangers, many people made a good living from the sea, and some even became very wealthy from it.
So, what was life at sea like for the medieval sailor?
Medieval Ships
During the early Middle Ages, up until the C11th/C12th, most ships sailing the north European seas were of Nordic design. These were ships constructed in the tradition of Viking longboats and knarrs. However, by the C12th ships of this sort were gradually phased out in favour of the classic medieval cog. When most people are asked to imagine a medieval ship, it is usually the cog that springs to mind. Indeed, the cog came to dominate north European maritime shipping from the C12th right up until the late Middle Ages.
Late in the Middle Ages new designs of ship began to appear in North European waters. These were carracks and caravels from Spain and Portugal. Initially the north Europeans were slow to adopt such ships, and it was left to the Italians, Spanish and Portuguese to pioneer their use. However, by the end of the Middle Ages they were an increasingly common sight.
Knarrs and Longboats
In the early Middle Ages, the best ships in northern waters were Viking ships. Their iconic longboats terrorised the seas but, of course, the Vikings, also engaged in extensive sea trade. Longboats were fine for carrying raiders, but when it came to transporting goods, they weren’t ideal. Instead, the Vikings used shorter, deeper, wider boats of similar design, called knarrs.
The knarr was versatile. Since most were not large, they could be used in rivers as well as at sea. A smaller knarr could even be transported overland in snowy conditions, much like a large sledge.
The knarr could carry a much larger cargo than the classic longboat. So, merchant ships of this sort soon became widely used across northern Europe. Knarrs typically carried cargos of up to around 30 tons (although a few later examples, such as the Big Ship of Wismar, could carry more). 30 tons sounds like a lot but compared to the bigger cogs and hulks of the later Middle Ages, it wasn’t that impressive.
Nordic ships (either knarrs or longboats) became the mainstay of maritime life, being widely adopted by all north Europeans, not just Scandinavians. They remained dominant right up until the C11th/C12th. The famous White Ship, which tragically sank in 1120, leading to the loss of the heir to the English throne, was constructed in this tradition.
Cogs
Medieval cogs first appeared in the C10th and by the C12th they were becoming an increasingly common sight. They eventually supplanted the old Nordic style ships, becoming the dominant design for most of the rest of the Middle Ages.
Cogs were clinker built (the hulls being constructed with overlapping planks), like the older Nordic ships. However, they were generally rounder and often larger. They usually had a single mast with a square sail and were steered by a single rudder at the stern. Unlike knarrs they were deeper and had closed rather than open decks. This allowed for storage of cargo (as well as space for the crew) below decks. Some were also fitted with characteristic medieval stern and forecastles, providing additional space and defensive platforms.
Tests on seaworthiness show that the cog was not necessarily more seaworthy, faster or more manoeuvrable than earlier ships. Indeed, they may well have performed more poorly in some respects. However, they could carry a larger cargo and had a defensive advantage when attacked (either at wartime or when facing pirates).
Medieval cogs were mostly used as merchant transports but, when fitted with stern and forecastles, they could be converted into warships. A typical cog might be 15 to 25 meters long, with a cargo capacity of 30 to 200 tons, although a few were much bigger.
Hulks
A second significant ship design employed at around the same time as the cog was the hulk (or holk). Hulks were of a very similar design to the cog. Major differences included the fact that they used median rudders, rather than a stern rudder. Such rudders may have made it easier to manoeuvre the hulk in certain conditions. These ships had no stem or stern posts, and some depictions show them with pronounced, high, curves at the stem and stern. In other respects, they were not unlike the cog, generally possessing a single square sail and sometimes fitted with stern and forecastles.
Hulks were never as widely used as the cog and only one wreck has survived the medieval period. As a result, our knowledge of these ships is quite limited and mostly comes from what we can glean from medieval illustrations.
Later in the Middle Ages, hulks were adopted by the Hanseatic League for use in merchant shipping. League hulks were very large and bulky, capable of transporting a significant amount of cargo.
It appears these ships were almost exclusively used for transport and trade rather than as warships. Hulks, like cogs, were eventually eclipsed by caravels and carracks by the end of the Middle Ages.
Caravels and Carracks
The very first caravels were used by the Portuguese in the C13th. The earliest caravels were used as small fishing boats but, over time, larger versions were constructed. By the C14th caravels capable of carrying cargos of around 30 tons were becoming more common. By the C15th they were ubiquitous in Portuguese coastal waters and their use was spreading fast across the Mediterranean.
Caravels differed from cogs in their sleeker design and their use of lateen (triangular) sails as well as square sails. In the caravel method of ship construction, hull planks were affixed edge-to-edge rather than in the old overlapping clinker-built tradition. Overall, caravels were faster, more agile and due to their sails, better able to sail against the wind. Over time larger versions were constructed such that by the C15th, caravels capable of transporting 50 to 60 tons of cargo were not uncommon.
Larger vessels, called carracks, were developed during the C14th and became increasingly common as the C15th wore on. These also used the caravel method of construction and lateen sails. These vessels could now carry large cargos on long sea voyages faster and more reliably than cogs or hulks. By the end of the C15th cogs and hulks disappeared from the seas as caravels and carracks became more popular.
Navigation
For most of the Middle Ages navigation techniques were crude. As a result, most captains preferred to keep the coast within sight as much as possible during a voyage. Knowledge of coastal shipping routes was passed on by word of mouth, by experience or in handbooks. For example, a C15th German mariner’s handbook described sea routes exclusively in terms of navigation with reference to topographical coastal features.
Out of sight of land, mariners were reliant on determining their position relative to heavenly bodies (assuming they were visible). In the early Middle Ages, most mariners had no compass and only crude tools to aid in determining their position. By the late Middle Ages, they were able to use tools such as astrolabes to more accurately determine a course. Crude compasses were used from the late C12th onwards. However, these consisted of a needle floating on water – difficult to use in rough seas to say the least! Naval compasses only became more widely used after the invention of the box compass at the start of the C14th.
Getting lost at sea was therefore a very real danger if a ship lost sight of land. This could happen in thick fog or if the ship was blown off course by a storm. If this happened the crew might find themselves in real trouble.
Coastal Shipping
Sea transport held a significant advantage over land transport throughout the Middle Ages. Ships could convey a large cargo from one English port to another, far faster than it was possible to move the same cargo over land. A heavily laden wagon might only be able to make 12 miles a day in good weather. A medieval merchant ship might cover a similar distance in a single hour. As a result, if it you needed to get your trade goods from one end of the country to another, sea transport was much faster and easier.
Most sea voyages made by medieval English sailors were therefore made along the British coast, taking cargo from one port to another. Such voyages were easier and safer than international sea trade. Since you did not need to cross the Channel, if a storm brewed up you could usually take refuge in a nearby port. Hugging the coast for the entire journey made navigation easier and, travelling close to England reduced the risk of attack from foreign enemies or pirates.
However, whilst local coastal trade formed the bulk of maritime traffic, international trade was vital for medieval England.
International Sea Trade
Throughout the Middle Ages, the Plantagenets maintained lands in France as well as England, Wales and Ireland. As a result, Calais became a crucial port through which the wool trade flowed to the continent.
The Plantagenet kings also held significant lands around the port of Bordeaux in southwestern France. Trade between Bordeaux and English ports like Bristol, Plymouth and Weymouth/Melcombe Regis in the southwest accounted for a significant proportion of international sea voyages. Bordeaux was a major source of wine imports. During the early fourteenth century, England regularly imported over 20,000 tons of wine a year from Bordeaux.
Aside from France, a significant volume of sea trade was conducted with Flanders, Scandinavia, and the Hanseatic ports of northern Germany and the Baltic.
Trade could, on occasion, take the English mariner even further afield, to ports along the Spanish and Portuguese coast and on into the Mediterranean. Voyages as far afield as North Africa, Italy and even the Levantine coast were less common but not unknown. Such voyages would have involved long periods at sea, risking the hazards of storms, becalming, pirates, disease and malnutrition. Risky as such long voyages might be, many people became very wealthy from such trade.
Life at Sea
Life at sea, especially on longer voyages, was hard. In winter sailors would spend most of the journey cold and wet. In the early Middle Ages, ships had no below decks space within which to take refuge from bad weather. The only protection from the elements you had was a tent or tarps, rigged over a section of the deck.
Cogs and hulks at least had enough space below decks for the crew to take refuge from the worst storms. It was still an unpleasant environment, however. In a storm the ship would rock violently, upsetting chamber pots (and their contents). Ships had a latrine at the bows, but these were very dangerous to use in bad weather. In summer, severe heat could make conditions below decks unbearably stifling. And, of course, most ships suffered from rat infestations.
By all accounts medieval sailors were a rough crowd. Drunkenness and fighting were perennial challenges at sea. Captains often resorted to harsh punishments to maintain order. The old sea laws of Richard I mandated that murderers should be tied to the corpse of their victim and tossed overboard. Those guilty of disorder were trussed up and dunked in the sea three times, running a real risk of drowning.
Storms and Bad Weather
Storms at sea were a serious threat to medieval shipping. They could blow a ship off course, sometimes resulting in the crew becoming lost at sea. They might even blow the ship onto rocks, resulting in a shipwreck and the loss of all hands. Not all rocks were well charted and only a few were marked with lighthouses, making it much easier to run into them, especially in poor weather conditions.
Bad weather could greatly impact the length of a voyage. Under normal conditions it was possible to cross the English Channel to Calais in less than a day. However, bad weather and unfavourable winds could easily extend your voyage. In one case, a ship caught in bad weather took over two weeks to make the crossing.
Whilst storms represented an obvious hazard, becoming becalmed could be just as dangerous. Ships often travelled with minimal supplies to free up more space for cargo, so significant delays ran a real risk of running out. If a ship was becalmed for long enough, the result could be fatal.
Piracy
The practice of piracy was endemic in the English Channel throughout the Middle Ages. A ship attacked by pirates could expect to see its valuables stolen at the very least. If the crew on the plundered ship were fortunate, they might survive largely unharmed, perhaps being put ashore. If they were unlucky, they were slaughtered and thrown overboard.
As to who exactly was ‘a pirate’ was a very grey area. Many ships that engaged in piracy also engaged in legitimate sea trade. Indeed, the act of piracy was often perpetrated by ships owned by one powerful lord against ships owned by a rival. Such private, often tit-for-tat, ‘feuds’ were not unlike the violent disputes between rival nobles that occasionally erupted on land.
In times of war, private ships were often recruited into royal service to harry enemy shipping as semi-official privateers. This was especially common during the Hundred Years War, when privateers were commonly engaged by both sides. And, when a truce finally came, privateers were routinely offered full pardons.
The lack of any adequate policing, coupled with crown reliance on merchant-privateers, prevented any significant clamp down on piracy in the Channel.
War
In medieval times naval battles on any scale were a rarity. Warships were primarily used to transport and escort soldiers destined for use in land campaigns. North European warships lacked weaponry capable of sinking each other. Thus, in the rare naval battles of the Hundred Years’ War, soldiers would attempt to board enemy ships and overwhelm the defenders.
Medieval English warships might contain a mix of soldiers. Longbowmen could pelt enemy ships with arrows whilst men-at-arms attempted to board and engage the enemy in hand-to-hand combat. To facilitate this form of warfare, ships often featured forecastles and sterncastles to serve as platforms from which archers might fire. To provide extra cover, these archers often affixed shields around the top of the forecastle and sterncastle.
In the late Middle Ages, warships might include early firearms in their armoury. These were usually small cannons and handguns used as anti-personal weapons, rather than larger artillery pieces capable of damaging enemy ships.
Larger artillery pieces began to appear only in a limited way in the late Middle Ages. Henry V’s huge flagship, the 70-meter-long Grace Dieu, had only three large cannons, mounted at the prow. Even large cannons of this sort were rarely used to fire on enemy ships. They were primarily intended for use in bombarding enemy coastal fortifications.
The Age of Discovery
In 1492, a carrack called the Santa Maria carried Columbus to the Americas. It marked the most famous achievement in the early period of what we now call the Age of Discovery. By the late C15th naval technology in the form of the carrack and new navigational aids made a trans-Atlantic crossing possible. Such a voyage would have been extremely challenging using the old medieval cogs and the cruder navigational techniques of earlier times.
In 1498, Vasco de Gama opened a trade route from Portugal to India, around the Cape of Good Hope. Again, such a hazardous journey was only possible using the new technology of his age. It was yet another sign that the world was changing.
Over the next two centuries, Europeans would strike out on long sea voyages to explore and colonize the far corners of the world. The Age of Discovery heralded the end of medieval Europe and the dawn of a new early modern world.
Keep up to date with our stories…
If you like reading our work and would like to keep up to date with the latest stories and news from our blog page, you can follow us on Facebook. We always announce any news and promote new stories as they are published here:
https://www.facebook.com/MedievalHistorian
If you are interested in life in medieval times, you might be interested in some of my related articles…
The Landscape of Medieval England
Medieval Summer Folk Traditions
References and further reading
Hanseatic League History & Civilisation, Athanasios Kouzelis, Kulturlandskapet, 2020
Knarr vs Cog: A shipshape evaluation. Hernandez Monfort, Jaume, 2023
Images
Medieval ship and compass, Jehan de Mandeville, 1403 (via wiki commons)
Modell Knorr from the Haithabu Museum, photo by Europabild (via wiki commons)
Bremen Cog, photo by VollwertBIT, 2007 (via wiki commons)
Model Hulk from gdańskiego, photo by Jerzy Litwin, 1969 (via wiki commons)
Santa Maria, photo by Filo gen, 2017 (via wiki commons)
Battle of Sluys, illustration from Jean Froissart’s Chronicle, C15th (via wiki commons)