The Age of Storms

The north of the island was not always the snowy wastes it is today. Several centuries ago, the peace of the Age of Glory was shattered when unnatural ice sheets started working there way south from the far north of the island.
Starting in the north, past the island out into the natural glacier, it slowly encroached over several decades and at first it went unnoticed as that part of the island was sparsely populated even at that time. However, over decades it had overtaken a lot of the island and was starting to effect the major settlements and crops in the north.
All attempts at trying to magically find the source failed so this prompted adventurers and expeditions to be sent north, what they discovered is now known to be the influence of Stygia, the 5th layer of the Nine Hells, coming through the barriers between planes - ushered through by the previous Archduke Geryon. Though his motives unclear, some believe he was trying to win back favour with the other rulers of the layers after he had fallen out of favour and had been replaced.
Once discovered, the most powerful people in world faced him, and a great battle ensued but end with him being banished back to the Nine hells and left the ruins of his castle buried beneath the ice. Most of the ice down the country slowly melted and went away however some of his influence is still left to his day, by the inhospitable north of the world is now known as The Everglacier and the north of the island has earned the name the Frostbreath due to the now unmelting nature of the area now