At the end of the Viking Age the establishment of three separate Nordic kingdoms hardly seemed a self-evident course of future events. The prospect of direct Danish rule over most of southern Scandinavia, combined with an indirect overlordship of other parts of the region, must have appeared at least as likely. Yet, in the course of the early Middle Ages the kingdoms of Norway and Sweden came to comprise most of their later territories on the Scandinavian peninsula and developed far enough for their survival to be secured. During the same period Christianity was firmly established in all Scandinavian-speaking communities and its Church reached the organisational stage where bishops ruled territorial bishoprics from permanent sees with cathedrals, monastic institutions were firmly established, and payment of tithe was being introduced. From the beginning of the twelfth century the Nordic churches were also organised as a separate church province under the supremacy of the archbishop of Lund (Part II).

All this does not mean that the political and ecclesiastical situation was stable at the onset of the high Middle Ages in the mid-twelfth century. The three kingdoms lacked centralised systems of government and their unity was seriously threatened by dynastic rivalry and succession disputes. In Iceland the original distribution of power among numerous chieftains within an all-embracing community of laws was in the process of being disrupted by the concentration of power in the hands of a small number of prominent families whose leaders ruled territorial lordships. As a separate legal entity on a smaller scale, the archipelago of Føroyar seems to have been dominated by chieftains and large landowners.

The word ‘Scandinavia’ first occurs in the Naturalis historia of Pliny the Elder (d. AD 79), in the form of Scadinavia or Scatinavia. In later manuscripts of this work an n was added in the first syllable and the name became Scandinavia, as it still is. Pliny used the name to denote what he believed to be a large island in the Baltic. As the basis for his original Latin version of the name, a Germanic form *Skapin-aujō or *Skaðin-aujō has been reconstructed. The last part of this compound, meaning ‘land on the water’ or ‘island’, causes no difficulty, but the interpretation of the first element is disputed. Half a score of conjectures have been suggested. One of the more plausible ones, accepted by some of the leading scholars in the field, is that the first part is derived from the Germanic stem of *skaðan – ‘danger, damage’. Scandinavia would then originally mean ‘the dangerous land on the water’ or ‘the dangerous island’.

Pliny also refers to a group of islands in the north called Scandiae. In the following century they reappear in the geographical writings of Ptolemy. He places the four islands of Skandiai east of Jylland (Jutland) and singles out the largest and most easterly as the proper Skandia. This is clearly Skåne (Scania), the southernmost region of present-day Sweden, and the territory north of it; the other three and smaller Skandiai would be Danish islands. It appears, then, that Pliny’s Scadinavia was also one of the islands which he called Scandiae.