Viking Warships & Naval Battles
Viking warships (langskip) were long, narrow ships driven by both oars and a square sail and built to carry many warriors fast, while the broader knörr merchant ships relied on the sail and carried cargo. This guide covers how those ships were built (clinker-planked hulls of oak or pine) and how the Vikings actually fought at sea: lashing ships together and boarding to clear the enemy’s deck.
Ships are what made the Viking expansion possible. Without them there would have been no raids on the coasts of western Europe, no trade routes to the east and no settlements in the North Atlantic. Shipbuilding was not the only Viking skill, but it was the one that carried all the others: raiding, trading and settling all began with a ship.
One of the earliest raids recorded in England struck the monastery of Lindisfarne in 793, and monasteries made easy targets: rich, close to the sea and undefended. The ships gave the raiders surprise. A longship drew so little water that it could sail right onto a beach or far up a river, so a crew could land, strike and be gone before anyone raised a defence.
The same building tradition served many purposes: carrying warriors, taking goods to market and crossing open ocean as well as rivers. Ships mattered enough to appear in Viking art. Coins minted in Scandinavia around 800, the so-called Hedeby coins, carry ship motifs, and the picture stones of Gotland often show ships.
The best-preserved originals are the Oseberg and Gokstad ships, dug out of Norwegian burial mounds and kept in Oslo in the Viking Ship Museum at Bygdøy, which is closed for rebuilding and reopens as the Museum of the Viking Age in 2027. These are the real ships, not copies. Full-size sailing reconstructions, such as the five Skuldelev reconstructions at the Viking Ship Museum in Roskilde, show how such ships behaved on the water.
Main Differentiation - Two Classes
Ships for warfare purposes were called warships or langskip, and those built for trade were merchant ships or knörr.
The warship was long and narrow, at least five times as long as it was wide by the Roskilde museum's archaeological definition, and it was driven by both oars and a single square sail. It was built for speed and for carrying a large crew of warriors. The merchant ship was broader and fuller, relied mainly on the sail and needed only a handful of crew. It was not entirely without oars: the coastal trader Skuldelev 3 has five oar ports, and the museum says its oars were used for manoeuvring and for short trips in calm weather. Cargo ships had half decks fore and aft with an open hold amidships.
The Warships
The Oseberg and Gokstad ships are the most famous, but they come from burials of 834 and about 900 and are broader in proportion than the longships of the late Viking Age. One of these later longships is Skuldelev 5, a small longship built in Denmark shortly after 1024: 17.3 metres long and 2.5 metres wide, with a draught of only 0.6 metres. The Roskilde museum calls it one of the smallest longships in a war fleet, suited to Danish coastal waters and the short, choppy waves of the Baltic, and thinks it may be a snekkja, the smallest class of warship named in the written sources.
Skuldelev 5 had 26 oars, 13 a side, and a crew of about 30. Along its top plank are fragments of a shield rack, a wooden batten behind which the crew could set their shields, and this is how the museum knows it was a warship. The great longship Skuldelev 2, built near Dublin around 1042, was about 30 metres long, with 60 oars and a crew of 65 to 70.
Did shields really hang along the sides at sea? The Gokstad ship was buried with 32 shields on each side, painted alternately yellow and black. But Ingvald Undset's 1898 guide to the Gokstad ship points out that the shields hung low enough to cover the oar holes, so they were taken down whenever the ship was rowed; he thought they were put up for burial and for festive occasions. The Roskilde museum, reading the skaldic verse alongside the finds, concludes that shields cannot have been mounted while a ship was rowed, and hardly while it was sailed. A row of shields belonged to a ship at rest or on show.
The Gokstad ship
The Gokstad ship, built around 890, is 23.22 metres long and 5.18 metres wide, with 16 oar holes on each side and room for a crew of up to 67, according to the Museum of the Viking Age in Oslo. Undset gives the ship's oars as 5.30 to 5.80 metres long, made of spruce, lighter than the oars of his own day and with fairly small blades, and he judged that each was handled by one man. The Oslo museum now reckons two men to each oar, which is how it reaches its crew of up to 67.
The oar holes are cut through the third plank from the top. Each has a slit on its after edge so the blade could be passed through from inside the ship, and several of the holes are still closed with their wooden ports, small covers that kept the sea out when no oar was in place.
The deck was made of loose pine planks that could be lifted, so the crew could get at the bilge and bail. There are no remains of rowing benches, and the Oslo museum thinks the rowers probably sat on chests that also held their gear.
Sail, oars and speed
A longship carried one square sail, and its oars let it move without wind, hold its place in a fjord or come in against a shore. That combination is what made raiding work: the ship could reach a coast under sail, land its crew and leave again quickly.
The Roskilde museum has rebuilt both Skuldelev warships: Skuldelev 5 as Helge Ask and Skuldelev 2 as the Sea Stallion from Glendalough. It gives Skuldelev 5 an average speed of 6 to 7 knots and a top speed of about 15 knots, close to 28 km/h. For the heavy cargo ship Skuldelev 1, the museum's Danish and German pages give an average of about 5 knots and a top speed of about 13; its English page on the reconstruction Ottar estimates a maximum of 10 knots under sail and no more than 1.5 knots under oars.
The Naval Battles
Sea battles in the sagas are fought much like land battles. The best-known account is Snorri Sturluson's description in Heimskringla of the battle of Svolder in the year 1000, where King Óláfr Tryggvason of Norway fought the kings of Denmark and Sweden and Earl Eiríkr Hákonarson. When the enemy fleet rowed out, Óláfr ordered his men to lower the sail and refused to flee, and his ships waited for the attack where they lay. Missiles and hand-to-hand fighting went on together: Snorri describes men shooting arrows and throwing spears and anything else that would serve as a weapon, so thickly that it was hard to keep a shield up against them.
The defending fleet lashed its ships together. At Svolder Óláfr had his ships lashed together at the stems, with his own Long Serpent in the middle and the Short Serpent and the Crane on either side, so that the fleet became one broad fighting platform.
The attackers took the lashed line apart from the outside in. Earl Eiríkr laid his ship, the Barði, alongside the outermost of Óláfr's ships, cleared it, cut it loose from the lashings and moved on to the next, while the warriors on the smaller ships fell back onto the bigger ones. At the end, when the earl's men had boarded the Long Serpent and most of its defenders had fallen, Óláfr and his marshal Kolbjörn jumped overboard, and Snorri says the earl's men had placed small boats around the ship to kill those who leapt into the sea.
The aim was to clear the enemy's decks, not to sink his ships. A captured ship was a prize: after Svolder, Snorri says, Earl Eiríkr took the Long Serpent for himself and steered it away from the battle.
Landing on a beach
Because the warships drew so little water, they could run straight onto a beach or a gravel bank. Skuldelev 5 had a draught of just 0.6 metres. A skaldic verse praises Knútr the Great for letting his longships run aground on gravel and sand in England.
Merchant ships - knörr
Cargo ships were built the same way as warships but to a different shape: shorter, broader, deeper and fuller. Skuldelev 3, a small coastal trader built of Danish oak around 1040, is 14 metres long and 3.3 metres wide and could carry about 4.6 tons of cargo with a crew of five to eight. The museum gives it an average speed of 4 to 5 knots and a top speed of 8 to 10.
For the open sea there was the larger cargo ship. Skuldelev 1 was about 16 metres long and 4.8 metres wide, built of pine in the Sognefjord area of western Norway around 1030, and needed a crew of six to eight. Its reconstruction, Ottar, carries about 20 tons, more than four times the load of Skuldelev 3, and the museum says the original could have sailed the North Sea, the Baltic and the North Atlantic.
How long did an ocean crossing take? Landnámabók, the Icelandic Book of Settlements, says it was seven dægr of sailing west from Stad in Norway to Horn in east Iceland; a dægr is usually read as a twelve-hour stretch. The Roskilde museum notes that, according to the written sources, the knarr was the only type of ship that sailed to Greenland.
Skuldelev 1 had decks fore and aft and an open hold amidships. It was not strictly a sail-only ship either: its reconstruction, Ottar, can be rowed with four long oars for manoeuvring in harbour and in calm weather, though only slowly.
A loaded cargo ship sat deeper in the water than a longship. Even so, the Roskilde museum notes that Skuldelev 1 drew less than a metre and a half even when loaded, so it could still work its way into shallow bays and up rivers.
The eastern routes meant crossing land. The Byzantine emperor Constantine Porphyrogenitus, writing around 950, and the Nestor Chronicle, written in Kiev around 1100, describe Scandinavians on the Dnieper hauling their ships overland past the worst rapids. When the Roskilde museum tested this in 1996, 27 men pulled the two-ton Helge Ask across a 300-metre neck of land in 15 to 16 minutes.
What counts as a longship
The Roskilde museum defines a longship as a ship driven by both oars and sail and at least five times as long as it is wide. Long, slender rowing ships without sails were already being built in the Iron Age, before the Viking Age. Some early Viking ships that carried both oars and sail are much broader, and the museum reads them as all-round vessels for trade and war alike.
The longships found so far vary a great deal in size. The ship buried at Ladby on Funen in the early tenth century was more than 21.5 metres long; the warship from Hedeby harbour, built around 985, was over 30 metres long and very slender; and Roskilde 6, found in 1997 while the museum harbour was being dug, was about 36 metres, the longest Viking ship yet found.
The sagas size ships by their rúm, the rowing spaces between the frames, each holding one pair of oars. Snorri gives Óláfr Tryggvason's Long Serpent 34 rúm, and the sagas name about 15 great ships with 30 pairs of oars or more between about 1000 and the middle of the thirteenth century. The Roskilde researchers caution that Snorri, writing around 1230, was probably describing the ships of his own century.
Skeið, snekkja and dreki
The skaldic poems use several words for warships. Skeið is the commonest, found in at least 49 stanzas, nearly all of them about war. Snekkja seems to be a different type, and in one poem a snekkja is smaller than a skeið. Dreki, 'dragon', is probably not a type at all but a poetic name for a great warship, in the same way that Óláfr's ship was called Ormr, 'serpent'.
How the ships were built
Viking ships were clinker-built: each plank overlaps the one below it, and the two are riveted together with iron. Shipbuilders preferred oak where they could get it, but in western Norway they built in pine, as the pine planking of Skuldelev 1 shows. The planks were split along the grain rather than sawn, which let them be thin and still strong: on the Oseberg ship the planks below the waterline are only two to three centimetres thick. Undset notes that the seams of the Gokstad ship were caulked with yarn spun from cow's hair.
Iron was part of the method early on. The Oseberg ship, built around 820, is already fastened with iron rivets, and the Sea Stallion, the reconstruction of Skuldelev 2, took 8,000 rivets, 600 litres of tar and 14 oak trees for the planks alone. The ships did change over time. Later longships had fixed cross-beams for the rowers to sit on, which the older Oseberg and Gokstad ships lacked, and by the late twelfth century the great ships had grown higher and broader rather than longer.
Shipbuilding was one of the great Viking achievements. Ships carried them to England and Ireland, along the rivers of eastern Europe and across the Atlantic to Iceland, Greenland and as far as North America. They kept the settlements overseas in touch with each other and made the trade routes between them possible.
The ships were not the whole story, though. Building a ship like Skuldelev 2 took timber, iron, tar, wool, hemp and a great deal of organised labour, and the Roskilde museum reads the scale of those resources as a sign of the power needed to gather them.
Resources
The Viking Ship Museum, Roskilde: The five Viking ships (Skuldelev 1, 2, 3, 5 and 6)
The Viking Ship Museum, Roskilde: Findings of longships from the Viking Age
The Viking Ship Museum, Roskilde: The longship in the medieval saga texts
The Viking Ship Museum, Roskilde: The longships in scaldic verse
The Viking Ship Museum, Roskilde: Ottar, reconstruction of Skuldelev 1
Museum of the Viking Age, Oslo: The Gokstad Ship
Museum of the Viking Age, Oslo: The Oseberg Ship, a Magnificent Vessel
Ingvald Undset, A Short Guide for the Use of Visitors to the Viking-Ship from Gokstad, 1898
Snorri Sturluson, Heimskringla: Óláfs saga Tryggvasonar, ch. 88 and 102 to 113 (Old Norse text)
Landnámabók, part 1 (Old Norse text)
Keep exploring: for the full range of vessels and their names see our guide to the types of Viking ships, or shop our Viking jewelry.
Viking Ships FAQ
What's the difference between a Viking longship and a knorr?
Longships (langskip) were long, narrow warships, at least five times as long as they were wide, driven by both oars and a square sail and built to carry many warriors fast. Knorrs (knörr) were broader merchant ships that relied mainly on the sail, carried cargo, and had only a few oars for manoeuvring in harbour.
How fast were Viking ships?
It varied by ship type. The Viking Ship Museum in Roskilde gives the small longship Skuldelev 5 an average speed of 6 to 7 knots and a top speed of about 15 knots. It gives the coastal trader Skuldelev 3 an average of 4 to 5 knots and a top speed of 8 to 10, and the ocean-going cargo ship Skuldelev 1 an average of about 5 knots and a top speed of about 13, though for its reconstruction Ottar the museum estimates 10 knots at most under sail.
Were Viking ships used only for warfare?
No. Longships (langskip) were built for raiding and war, while knorrs (knörr) were merchant ships for trade and cargo. Some early Viking ships with both oars and sail were broad enough that archaeologists see them as all-round vessels, used for trade and war alike.
How did Vikings fight naval battles?
In the saga accounts, such as Snorri Sturluson's description of the battle of Svolder, the defending fleet lashed its ships together into one fighting platform. The attackers laid their ships alongside, cleared the outermost ship by boarding and hand-to-hand fighting while others shot arrows and threw spears, then cut it loose and moved on to the next. The aim was to clear the decks and take the ships, not to sink them.