The actual age of the kingdom of Sweden is unknown. Establishing the age depends mostly on whether Sweden should be considered a nation when the ''Svear'' (Sweonas) ruled Svealand or if the emergence of the nation started with the ''Svear'' and the ''Götar'' (Geats) of Götaland being united under one ruler. In the first case, Svealand was first mentioned as having one single ruler in the year 98 by Tacitus, but it is almost impossible to know for how long it had been this way. However, historians usually start the line of Swedish monarchs from when Svealand and Götaland were ruled under the same king, namely Eric the Victorious (Geat) and his son Olof Skötkonung in the 10th century. These events are often described as the consolidation of Sweden, although substantial areas were conquered and incorporated later.