Sweden was the last of the Scandinavian kingdoms to be established, and it is also the country about which the least is known. This is partly because the country, remote from the continent and the British Isles, naturally looked to the east and the emergent kingdoms and rather less literate cultures of the Baltic and Russia. However, it is known that during the Viking Age, Sweden essentially consisted of two separate kingdoms: in central eastern Sweden, the kingdom of the Svear tribe, around modern Stockholm and Uppsala, and in the west, the kingdom of the Gotar tribe, part of the modern provinces of Vastergotland and Ostergotland. These two areas were effectively divided by a large tract of heavily wooded and marshy land. Gotaland was less remote than Svealand, and there seems to be evidence of contact between Gotaland and the kingdom of Denmark, quite natural given the importance of sea communications in this period and the difficulty of land travel.
The first kings of Sweden whose names are known are mentioned by a Frankish writer called Rimbert. Rimbert was the author of the ninth-century Life of St. Ansgar. The Ansgar that he wrote about was his deceased mentor and a Christian missionary from Frankia, who was welcomed by a King Bjorn and later a King Olaf to the important Swedish trading town of Birka in the 820s and 850s respectively. How much power they had in Svealand is unclear, but the kings of the Svear do seem to have been sufficiently powerful to control the Baltic islands of Gotland and Oland by the end of the ninth century. The first king who is known to have exerted power in both Gotaland and Svealand is another king called Olof. His nickname was Skotkonung (“Tribute-King”), which suggests a degree of political subservience (see Olof
Skotkonung). Olof’s reign can be dated roughly to the period 995-1020, and he issued his own coinage from the new royal center at Sigtuna, proclaiming himself as a Christian king of the Svear. Nevertheless, many of his subjects appear to have still been pagan—and in the 1070s the German writer, Adam of Bremen, records that pagan rituals were still taking place at the cult center of Gamla Uppsala. Olof’s power was not unchallenged, and he seems to have lost control of Svealand at some point. He was, however, succeeded by his son in Sigtuna, Anund Jakob, and when Anund died around 1050, his halfbrother Emund, another son of Olof, became king. While these kings exercised some power throughout the country, it is really not until after the Viking Age, in the 1170s, that the whole of Sweden was properly united under one king—Knut Eriksson.