On the island of Kungshatt, Sweden, there is a tall pole with a large hat on top. It's been there since the 17th century, although it has been replaced a few times. The name Kungshatt translates to "King's Hat," and thereby lies a tale. The king in this tale was the 9th-century Swedish ruler Erik Anundsson, whose reign was long and filled with conquests of nearby lands, which could not easily be explained by mere military strategy, number of troops, and bravery. Well, maybe it could be, but the tale of the hat is a better story.
The answer to this comes to us in a local legend in the Mälar Valley region of Sweden – the very heartland of the old Swedish kings. According to this tale Erik was so successful on his raids and campaigns because of his allegedly magical hat. We do not know from where he acquired this hat, but we are told of its magical properties. When Erik wore this hat, handily he could control the winds and the weather by simply turning the hat in any given direction. This was, of course, quite useful in the Viking Age when the main way of transportation was by ship and when sudden attacks by sea could be incredibly devastating. The powers of the hat increased the king’s prestige and he would no longer be called “Erik Anundsson” … He became Erik Weatherhat! We’ll leave it to you to decide whether his hat was actually magical or just made him look magically dapper.
Whatever the case, years passed and Erik became a rich and powerful king through plundering and subjugating the east, much due to the magic of his powerful hat. As he grew older, however, his earlier humility had left him and he had become very ambitious, and now sought to rule the west as well. He made plans to greatly expand the Swedish realm by incorporating the disputed regions in modern-day western Sweden, and even to conquer another country – Norway.
Weatherhat’s ambition was to create a kingdom as great as that ruled by the Swedish king Sigurd Ring and his son Ragnar Lothbrok. Apart from western Sweden, this also meant conquering the area of Viken in what was then southern Norway. This land was, however, already ruled by a king called Harald Fairhair, who was to become Erik’s greatest rival- someone with magnificent hair always being greater than one who merely wears a hat, no doubt to hide hideous baldness…
One may think that realms conquered mattered more than a rivalry over headgear, but in any case, the battle between Erik and Harald led to the hat on a pole in Kungshatt according to local legend, which you can read at Today I Found Out.