The warriors of Dowdun Reach were skilled in the manipulation of mithril metal. They made swords, axes, and great hammers that could crush their enemies flat. They crafted impressive suits of armour, though they favoured the more sinister-looking black armour than the mystical-looking mithril.
One Zamorakian blacksmith, a man called Bob, like so many people on Gielinor, crafted the first mithril medium helm to very little fanfare. He would wear it at every meeting, he would show it off at all the big events, all to impress the women of the keep. You can imagine how well that went.
Not very well, for clarity's sake.