Sweden is first described in a written…
45 BCE to 99 CE
In Germania 44 and 45 he mentions the Swedes (Suiones) as a powerful tribe (distinguished not merely for their arms and men, but for their powerful fleets) with ships that had a prow at each end (longships).
Which kings (kuningaz) ruled these Suiones is unknown, but Norse mythology presents a long line of legendary and semi-legendary kings going back to the last centuries BCE.