The consolidation of Sweden was a long process during which the loosely organized social system consolidated under the power of the king. The actual age of the Swedish kingdom is unknown. Also, for various reasons, scholars differ in characterizing early Sweden as a country, state or kingdom by definition.
Unlike the history of Norway and Denmark, there is no agreement on a reliable date for a "unified Sweden". Historians judge differently the sources for the history of Sweden's consolidation. The earliest history blends with Norse mythology. Early primary sources are foreign; secondary sources were written at a later date.
In both Medieval Icelandic sources and contemporary Swedish sources, Götaland and Sweden were separate nations. In Sögubrot af Nokkrum
for instance, Kolmården between Svealand and Östergötland is described as the border between Sweden and Östergötland: "Kolmerkr, er skilr Svíþjóð ok Eystra-Gautland". Also, in Hervarar saga
, king Ingold I rides from Västergötland to Sweden through Småland and Östergötland: "Ingi konungr fór með hirð sína ok sveit nokkura ok hafði lítinn her. Hann reið austr um Smáland ok í eystra Gautland ok svá í Svíþjóð." The lord Bo Jonsson Grip was probably best acquainted with the geography of the Swedish Kingdom since he owned more than half of the land in the region. In 1384, he stated in his will that the kingdom consisted of Swerige (Sweden, i.e. Svealand), Österland (i.e. Finland) and Göthaland (i.e. Götaland).
To solve the problem of defining an early history of Sweden that coincides with reliable sources, a group of modern Swedish historians have narrowly defined stat (based on the concept state), using Christianity as a necessary and sufficient condition for a stat. The same connection between Christianity and consolidation is used in other countries where written sources are less scarce, such as England or Harald Bluetooth's Denmark. The definition is based on the fact that English and German priests would have brought organizational and administrative skills, establishing the use of the abstract concept of a stat (including by local rulers). The process of consolidation would have required this important ideological shift. While an Iron Age Germanic king would claim the elective support of his people, and the Norse gods, a crowned Christian king would claim that his rule was divinely inspired.
That Sweden went through a process of consolidation in the early Middle Ages is generally agreed upon. The full and complete process of consolidation was only reached in the 17th century with the treaty of Roskilde and the treaty of Brömsebro, which annexed all the present-day territories. The current borders of Sweden, however, were not defined until 1809 with the loss of Finland to Russia in the Finnish War.