The first of the aboriginal Hyborian tribes to discover the use of stone in building, the Hyperboreans abandoned a primitive, nomadic way of life to settle in huge walled dwellings of stone, consequently founding the very first, but most isolated, of the Hyborian kingdoms. Separated from Asgard to the west by the River of Death Ice, the Hyperborea of Conan’s day was ruled by wizards and witches, a group known as the White Hand. Its tall, gaunt lords and ladies tended towards white hair and emerald eyes.
The citadels of Hyperborea were impressive even by Hyborian standards. They were made from mortarless stones carefully fitted together and dressed smooth to give no foothold for a climber. The walls were turreted and crenelated, fifty feet high and twenty paces thick, giving the fortresses a squat appearance. Windows and arrow-slits were set into the walls, too high to be entered, but low enough to allow effective defense. The ironwood gates were protected by iron portcullises and decorated with protective runes formed by patterns of iron nails.
The western boundary of Hyperborea with Asgard was the River of Death Ice, having its source in the Eiglophian Mountains. This stream was shallow, clogged by glacial debris. Since it was also frozen throughout the long winters, it provided an ineffectual barrier against invading Aesir from the west. The land of Hyperborea was wild and mountainous, gloomy and damp, its main pass through the mountains ominously named Skull Gate.
The Hyperborean people were pale-skinned, extremely tall and gaunt, with white hair and cat-green eyes. Many were as tall as seven feet. They were a superstitious lot who lived as serfs in huts and hovels beyond the stone walls where they eked out meager livings from farming the stubborn soil and herding small numbers of shaggy cattle and reindeer. Hyperborea was ruled by the White Hand—a coven of sorcerers not unlike the Black Ring of Stygia or the Scarlet Circle of Khitai which ruled the land from Castle Haloga in the far reaches of Hyperborea. The White Hand’s “Witch-Men” were also the priests and priestesses of Louhi, the ever-reincarnating goddess of the Hyperboreans, as well as accomplished sorcerers who received their arcane magical abilities from service to their goddess. Their magic focused around the cold of their land and necromantic control of the undead. Hyperborean sorcerers were highly prized in the northern wilds, but they were little respected in the rest of the Hyborian lands because they were viewed as having sold their souls for power.
Hyperborea also hosted several bands of hardy slave raiders who made repeated forays into Cimmeria to fill their slave pens. According to tales, Conan was taken captive by Hyperborean slave traders early in his youth. After the Age of Conan, Hyperborea was conquered by Hyrkanians who galloped around the frozen tundra north of the Vilayet Sea to lay the land to waste.
Unfortunately, we're not going to allow Hyperboreans as playable as there is really no justification for their being so far south as Shem. Seeing a Nordheimer or a Cimmerian would be a rare occurrence, but a Hyperborean would be a step beyond. Just listing information here about them for the sake of reference.