Evidence Suggests Vikings’ Ancestors May Have Begun Raiding in the 3rd Century

Pegs marking the post holes of two large boathouses on Rennesøy, north of Stavanger.

February

/ 2026

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The first Viking raid most people can name is Lindisfarne in AD 793, and this is generally taken as the beginning of the Viking invasions, certainly of the British Isles. But a new argument suggests Scandinavian sea power may have been organized centuries earlier. Norwegian archaeologist Frans-Arne Stylegar points to clusters of giant Iron Age boathouses - essentially ship hangars - dated to AD 180–540, and asks what they were really built for. His answer: not just local feuds, but North Sea raids that look like a “prequel” to the Viking Age.

Even if the case is still largely circumstantial (and Stylegar’s academic report is described as 'forthcoming') it’s the kind of hypothesis that forces a rethink. If these coastal bases did support North Sea raids, it suggests the Viking “shock” of the late eighth century had deeper roots in Roman-era networks, mercenary service, and shipbuilding know-how.

Boathouses Built for War - Not Fishing

Stylegar’s starting point is the sheer scale and density of Norway’s boathouses facing the North Sea and Skagerrak. Science Norway reports that archaeologists have recorded more than 800 such foundations, with many of the largest dated broadly between AD 200 and 800, and with key clusters in western and southern Norway, places well positioned for North Sea raids.

The logic is blunt: big sheds imply big ships, and big ships imply manpower and organization. Stylegar also suggests some of that organization may have been learned abroad, via Scandinavian service as mercenaries within Roman naval systems.

The Nydam Ship

The Nydam Ship, dendrochronologically dated to 310 to 320 AD. (Andree Stephan/CC BY-SA 3.0)

The Nydam Ship: a 4th-century clue to raiding fleets

Norway has no preserved warships from this early period, but Stylegar points to a famous near-miss across the water: the oak-built Nydam boat, dendrochronologically dated to AD 310–320 and found in a Danish bog as part of a sacrificial deposit of weapons and gear. The Early Medieval Archaeology overview notes it as the “oldest preserved early Germanic deep-sea rowing boat,” and argues its speed, manoeuvrability, and large crew made it suitable for swift operations along hostile coasts - exactly the profile expected for North Sea.

Science Norway is careful here: nobody can prove the Nydam ship was Norwegian, or that it ever crossed into Britain or Gaul. But the ship demonstrates that, by the early fourth century, northern communities could field purpose-built war vessels with crews in the dozens, technology and logistics that make the “too early for Vikings” argument harder to sustain.

Map showing places along the coast of Vestlandet, Sørlandet and Trøndelag County where large boathouses from the Norwegian Roman period have been found – possible naval bases. (Forthcoming, Stylegar, 2026/Science in Norway)

Roman Texts and Why “Saxons” May be a Label

Stylegar’s most provocative point is interpretive: he says late Roman Latin sources often blame “Saxons” for North Sea and Channel piracy in the fourth and fifth centuries, but that “Saxon” may be a broad label for seaborne warbands rather than a precise homeland. In Science Norway’s phrasing, “saxons” could refer to sea warriors, possibly named after the seax weapon, and potentially including groups operating from Norway’s coast.

Independent summaries of third-century raiding likewise emphasize how the Roman response took physical form along the coasts: fort building, patrol bases, and commanders appointed to counter seaborne threats. One long-form overview argues the “Saxon Shore Forts” and related measures show Roman authorities considered these raids serious even if individual fleets may have been relatively small by later medieval standards.

A “Viking Age” that Starts Earlier?

If Stylegar is right, the Viking Age didn’t begin with a sudden leap in ship design or warrior culture, but with a long build-up: Roman-era contacts, returning mercenaries, coastal bases, and raiding traditions that later scaled dramatically. It also reframes familiar themes explored in Ancient Origins features on the Saxons, the Vikings, and even the toolkit of weapons such as the seax.

For now, the safest conclusion is that the infrastructure for North Sea raids may have existed well before the famous monastery attacks of the late 700s, and that Scandinavia’s maritime “learning curve” during the Roman period deserves more attention. Whether historians will ultimately move the Viking starting line back to the third century is uncertain, but the ship sheds on Norway’s coast ensure the question won’t go away.

Top image: Pegs marking the post holes of two large boathouses on Rennesøy, north of Stavanger. Source: Jan G. Auestad / Museum of Archaeology in Stavanger/Science Norway

By Gary Manners