Hyperborea is the northernmost of the Hyborian kingdoms and also one of the oldest. The first organized Hyborian kingdom to emerge was Hyperborea. The tribe which established it entered their Neolithic age by mastering architecture. In particular they learned the secret of erecting buildings out of stone. The start was made for reasons of fortification. They built a crude stone fortress for the defense of their territory from prospective invaders. They were still nomads and lived in tents made out of the hides of horses. But soon abandoned them in favor of their first stone houses which were still crude but durable. They permanently settled themselves in fortified settlements and developed cyclopean masonry to further fortify their defensive walls.
The Hyperboreans were by then the most advanced of the Hyborian tribes and set out to expand their Kingdom by attacking their backwards neighbors. Many tribes lost their territories to them in wars and had to migrate away. Others fled the path of their expansion and started their own migrations before ever engaging them in war. Both migrating groups preferred this solution to becoming mere vassals to their powerful Hyperborean kin.
By the time of Conan, Hyperborea has a history lasting for thousands of years. But weather conditions have become harsher and the kingdom has declined. Hyperboreans often had to face invasions by the Aesir, the Vanir, the Cimmerians. Though they themselves were able to contact raids on Hyrcania and Zamora. The Hyperboreans maintain a number of developed cities: Haloga, Sigtona and Pohiola. The ruling class includes a number of powerful sorcerers and the land has at times been ruled by a Witch-Queen. The depiction of Hyperboreans has varied at times. From being " pale-skinned, extremely tall and gaunt, with white hair and greenish eyes" to being albinos. Their resources are meager but underestimating Hyperborea has doomed entire armies.
Hyperborea is landlocked. To the west are Aesgaard, Cimmeria, and the northernmost areas of the Border Kingdom. To the south are Brythunia and Zamora . The eastern borders are vaguely defined, since they end in a sparsely-populated Tundra. Various stories have depicted Hyrcanians and other nomads passing through. With the entire area being a target for Turan's expansionistic efforts. The areas to the north are mostly uncharted, presumed to be a frozen wasteland.