Vikingeborgen Trelleborg

How do we know? Our knowledge of the Scandinavian Viking Age stems from many and varied sources. Archaeologists, historians, biologists, geologists and many other scientists have contributed to our present understanding of the period through their combined efforts.
Archaeology
All over Europe new finds of Viking activity are frequently
discovered, such as traces of settlements and the graves of the
people. Very often the finds consist of everyday tools and artefacts,
but together with the rest of the finds from archaeological
excavations they add little pieces to the huge jigsaw of our
knowledge of Viking Age society.
During the past three decades, experimental archaeology has advance greatly. By using authentic building techniques and replicas of Viking Age tools, archaeologists have gained a better insight into the conditions of life and the function and use of, for instance, the ships and houses of the Vikings.
The writing of the Vikings
Viking Age writing was based on a runic alphabet consisting of 16
signs or “letters”. Most runes are short messages, which have been
carved into the surface of wood and bone or on large stones. The
texts on the rune stones often state the lands owned by and deeds
performed by deceased people. In this way, the runic stone is a
source of understanding of social ties, land ownership, and events.
Contemporary sources
Viking Age Scandinavia had no written literary tradition, unlike
Christian Western Europe south of the border. Among the most
important sources for understanding the life and society of the
Vikings are foreign chroniclers, missionaries and clerks, describing
their meetings with the people of the north. Especially important
are the written papers by Ansgar and Adam of Bremen.
Saxo and the Sagas
The Icelandic Sagas were almost exclusively written down during the
13th century. The Sagas deal with the period from the colonization
of Iceland to its Christianization around AD 1000. This is a vast
and important group of sources for the understanding of daily life,
legal thought and ideals. Another well known document is one by the
poet Snorre Sturlasson. In his work Heimskringla, Sturlasson speaks,
for example, about the colonization of Iceland.
In Denmark, Saxo Grammaticus wrote the History of the Danes around AD 1200. His famous chronicle was written on the order of the Archbishop Absalon, and the work is highly coloured by his political views. Common to both the Sagas and Saxo´s chronicles is that they were written two centuries after the events they describe. This, of course, diminishes their value as historical sources of the Viking Age.