Non-literate Viking culture has nothing to say to us on this difficult subject, but from the time the Vikings first came to the attention of the annalists in England, the view of their victims was insistently that they were engaged in an ongoing religious war. Though they were sometimes their place of origin, with ‘Danes’ serving as a generic term for all Scandinavians, sometimes ‘foreigners’ and sometimes ‘flotman’, ‘sæman’, ‘sceigdman’ and ‘æscman’ - all terms referring to their being seaborne raiders - with overwhelming frequency the Vikings were referred to in terms of their religion.
36
One hundred years after the first Lindisfarne raid, the Welsh bishop Asser, in his biography of Alfred the Great, continued to refer to those much larger bands of Scandinavian aggressors who had by then established themselves along the eastern seaboard of England as ‘the pagans’ (
pagani
), and to their Anglo-Saxon victims as ‘the Christians’ (
christiani
). Alcuin had sensed at once the real consequences of the 793 raid. ‘Who does not fear this?’ he had asked in his letter to Ethelred of Northumbria. ‘Who does not lament this as if his country were captured?’
4
‘The devastation of all the islands of Britain by the Heathens’
However we rank the reasons for the Vikings’ sudden and dramatic eruption into the written records of England and Ireland at the turn of the eighth century, there is little debate about the importance of the longship, with its large sail, in making such raiding possible. The story of the introduction of sail into Scandinavia as told by the Gotland picture-stones is of a slow evolution, taking place from the sixth to the eighth centuries, in which a rudimentary piece of cloth fastened high on a pole gradually turned into a sophisticated, full-sized sail, with a tall mast and ropes that gave a high degree of control over its tension and orientation to the wind.
1
Some might argue that the mere possession of a technological wonder like this, and the desire to exploit it fully, must be counted among the reasons for the onset of the Viking Age.
It is thought that boat-builders worked in pairs, perhaps with a master craftsman on one side and an apprentice on the other, who was able to watch and mirror his techniques. Tools used were mainly chisels, hammers, axes and a type of drill that rested against the breastbone as the handle was turned. Most of the work was done using the long-handled cutting axe, heavier than a hand-axe and with a short, almost straight edge. Builders of reconstruction boats report that the most arduous and time-consuming part of the work was the shaving and shaping of the boards, a job that called for the broad-edged ‘bearding-axe’.
Logs for ship-building were split with a club and wedge along the central pith rays that gave further splits into four, eight, sixteen and sometimes thirty-two parts. The advantage of this was that the integrity of the wood-fibre system was preserved, minimizing the penetration of water and providing good resistance to rot. It also made for a boat that was light in weight but flexible and strong, qualities that were perfect for the Viking raiding tactic of beaching in locations thought to be inaccessible to warships. The mild climate of those times produced huge oak forests, and the very large number of trees from which the boat-builder could choose meant that for those parts, such as the keel and hull of the boat, where a curve was needed, he was able to pick out a tree in which such a curve occurred naturally. This ability to ‘see’ the shape of a plank inside a growing tree must have been an essential part of the Viking Age boat-builder’s skill. A builder of reconstruction boats found that the use of naturally curving planks gave up to twenty times more resilience in the timber than planking that had been sawn to shape.
2
The keel could not be jointed, so the length of the timber dictated the length of the boat. A socket construction called the ‘mast-fish’ held the mast, which could be lowered and removed when not required, and the rectangular sails were made of wool reinforced with leather bands.
A characteristic of the longship was a steering-oar mounted at the rear on a small shaft on the starboard side (from the Old Norse
styrbord
, meaning ‘steering side’) of the ship. The familiar stern-mounted rudder of the modern boat is a more efficient navigational device, and since the Vikings had the technology to make the iron hinges on which to hang a sternpost rudder it is natural to wonder why they did not do so. The strongest advantage seems related to the shallowness of the draft, in that it enabled navigation in almost any type of water, from the open North Sea to the rivers and streams of Ireland, Francia, England and the lands east of the Baltic. Fully extended at sea, the oar hung vertically below the level of the ship itself in a leather strap and could be easily adjusted up or down to allow for differences in the depths of the water. It could also be loosened from the strap and stored horizontally when navigating in shallow waters, or prior to landing on a beach. It enabled ships to load or unload cargoes from a river bank, or when beached at low tide. The ease of removing it would enable boats to be dragged deep inland up narrow rivers and towed backwards to open water where there was no possibility of turning round, a manoeuvre that would be impossible for a ship with a rudder mounted on the sternpost.
3
The longship, high at both ends, with the large keel that was essential to maintain stability when crossing an ocean and its retractable side-oar that functioned as a rudder remains, for most people, the symbol of the Viking Age. The idea of the purpose-built vessel, in particular one designed for use as a merchant ship, does not seem to have arisen until a time somewhere between the building of the Gokstad ship in about 900 and of the five ships discovered at Skuldelev,
4
built around the middle of the eleventh century, that had been filled with boulders in their old age and scuttled to protect the approaches to the harbour at Roskilde, then the capital of Denmark. These were discovered and raised in the 1960s.
5
Taken together they offer a fairly representative selection of the range of ships in use in the Viking Age.
Each vessel revealed a different functional design: Skuldelev 1 was an ocean-going trading vessel, possibly a
knarr
, with decks fore and aft and open holds amidships. She would have been crewed by six to eight men. Regardless of size, ships were not fitted with benches and men would use their sea-chests to sit on when rowing. Skuldelev 2 was a longship that would have had a crew of about seventy men. It has been estimated that with sixty men manning the thirty pairs of oars (by way of comparison, Oseberg had fifteen) Skuldelev 2 would have been able to maintain a speed of about six knots for long periods of time. Under sail and in favourable wind conditions she could probably have reached twenty knots. Dendrochronological analysis shows that Skuldelev 2 was built from trees felled in a forest at Glendalough, north of Dublin, in about 1042. Skuldelev 3 was a small, oak-built trading and transport ship. She had an open hold with space for about four tons of cargo. Skuldelev 5 (Skuldelev 4 turned out to be part of Skuldelev 2) was a small longship of the type known as a
snekke
with thirteen pairs of oars and room for thirty warriors on board. Tests with a replica showed that, even when fully manned, she drew no more than 50 centimetres of water. Skuldelev 6 was a high-sided fishing vessel that probably also saw service as a ferry boat.
The Skuldelev ships were built mainly of oak, with ash and pine also being used, and in the ‘clinker-built’ style, working from the outside in, with each board overlapping the one below it and fastened to it with iron rivets. By contrast with the Oseberg ship, on which the fibres, up to 3 metres long, used by whales to filter the seawater for their food,
6
were used to bind her shipboards to the interior struts - something that gave her hull a remarkable flexibility - the Skuldelev ships were jointed with nails.
7
Caulking was done with moss and tar, and they all showed signs of having been repaired or adapted at some point in their lives, with rotten or damaged planks being replaced. Among the tools employed would have been a two-pronged iron ‘nail-seeker’ used to locate and cut rivet heads of the type found at the excavations of a Viking Age ship-building site at Paviken on Gotland.
8
No rigging has survived in any of the ship-graves discovered so far, and for our knowledge of the sails and rigging of Viking ships we are dependent on the picture-stones from Gotland, some of which, like the Alaskog stone and the Stora Hammars stone from Lärbro, show remarkable detail. A stone of unknown provenance shows a relatively rare representation of a longship with her sails reefed. Coins from the later Viking Age sometimes display longships, like the coin found in 2000 near Lake Tissø. The coin and a number of picture-stones show shields mounted on a ‘shield-rail’ running round the railing of the ship, like the sixty-four yellow and black shields buried with the Gokstad chieftain on his ship. Ship-building as an industry throughout the Viking Age must have been a major part of the daily life of very large numbers of a great many communities, and the foresters, carpenters, blacksmiths, sail-makers, rope-makers and labourers involved must have been legion; yet the sagas convey nothing of this. Perhaps it was the very ubiquity of its sights and sounds that left the industry unremarked, unless it were that their authors hailed mostly from treeless Iceland where little ship-building was done and old ships patched up and kept afloat for as long as possible.
The wealth of incidental detail concerning navigation scattered across
Heimskringla
and in the sagas suggests the use of techniques ranging from the simple plumbline to avoid shallows and the countless tiny and rocky
skjær
that form a natural barrier to so much of the Norwegian coastline, to the sophistications of a sun-compass. When crossing the open sea the Vikings would use ‘dead-reckoning’, a method of navigation that involved observing the latitude and estimating the longitude to give some idea of the total distance travelled. Latitude sailing necessitated the use of a navigational aid called a ‘sun-shadow board’. This was a wooden disc with a pin or gnomon at the centre that could be adjusted up or down according to the time of year. It was floated in a bowl of water and the shadow of the sun at noon noted. If the ship was on course then the shadow would reach a circle marked on the board. If it passed beyond, the ship was north of this latitude. Should it fail to reach the circle she was south of it and the skipper could make the necessary adjustments. A cauldron of the type found in the aft or ‘kitchen’ section of the Oseberg ship, when not in use for on-board cooking, could have been used to float the device. There is archaeological evidence in the form of a partial wooden disc, found in 1948 at Uunartoq fjord, near the Eastern Settlement, one of the two colonies established by the Vikings in Greenland in about 985.
9
It is marked with hyperbolas and sixteen small cuts crossing a long line that seems to indicate north. Dated to about 1000, in its complete form it would have measured about 7 cm in diameter, with thirty-two carved triangular points cut around its circumference. The shadow cast by the tip of a gnomon in the centre of the disc described different hyperbolas at different times of the year. In the few weeks of the year around the summer solstice, at latitude 62° north of the equator, rotating the disc until the shadow of the tip fell on the curve would give the general directions with sufficient accuracy to sail a bearing. A second and more complete sun-compass, dated to the eleventh century, was found at Wolin in Poland in 2002.
10
A reference in a late and literary source describes the use of a ‘sun-stone’, a mineral that occurs in several forms in Iceland with the property of polarizing light when held up in the direction of the sun.
Raudulfs tháttr
, a short story preserved in a manuscript from the early fourteenth century, describes the visit of the Norwegian King Olav Haraldson to the home of a rich farmer named Raudulf. Olav asked his host’s son Sigurd if he had any special talents, and the youth replied that indeed he did - he was able to tell the time, day or night, even when no celestial body was visible. The king was interested and on the following day, which was overcast, he challenged the youth to demonstrate his skills. Once Sigurd had done so, Olav ordered a sun-stone to be brought out and held up to the sky in the general direction the sun was thought to be. In the story the light streams through the prism and Sigurd’s remarkable talent is confirmed to the king’s satisfaction.
In general, there is uncertainty about the degree of astronomical knowledge the Vikings had. Oddi Helgason, a twelfth-century Icelander known as Star-Oddi for his knowledge of astronomical phenomena, kept an almanac with precise calculations of the occurrence of the summer and winter solstices and diverse other mathematical observations, but it is not known whether Oddi merely noted down knowledge that had been common in the far north since the ninth century, or was a genius responsible for the calculations himself.
11
Another enigma involves thirty lenses of rock crystal that are part of the collection of the Visby Museum on Gotland. Dating from the very late Viking period, and at first assumed to be ornamental trinkets, tests conducted on the lenses revealed that they had imaging powers as good as those of modern optics.
12
They had obviously been made on a turning lathe and were of such high quality that they could have been used as magnifiers, as fire-starters, to cauterize wounds, or even to make up the light-chain in a telescope. Their rarity has led to the supposition that they were not the work of a Viking Age craftsman but came originally from the more advanced workshops of Constantinople or ancient Persia. To all such speculations we can only add the further presumption that efficient and safe long-distance navigation involved for the Vikings a knowledge of the major landmarks observable on the longer voyages; of the direction and strength of currents at sea; of birds - particularly sea-birds - and of their environments and habits of flight; of cloud formations; of the use of both day and night sky as an almanac; as well as a developed sensitivity to the subtleties of sea, sky and weather well in excess of anything we possess now.