Dean's Reign of Winter
From “Snows of Summer”, Paizo Publishing, LLC
Exactly 1,400 years ago, a powerful witch from another world named Baba Yaga arrived on Golarion with her Dancing Hut, a formidable artifact that can travel between worlds and even between the planes. In a quick, brutal conflict known as the Winter War, the self-proclaimed Queen of Witches conquered the eastern Linnorm Kingdoms of Raemerrund and the Djurstor Confederacy and founded a new nation locked in eternal winter—the land of Irrisen.
After installing her daughter Jadwiga on the throne as Irrisen’s first queen, Baba Yaga departed in her Dancing Hut, but she returned to Irrisen exactly 100 years later to replace Jadwiga with a new daughter, Morgannan, taking the former queen and the first generation of her descendants with her when she left again. Baba Yaga has continued this tradition every 100 years for the last 14 centuries, resulting in a succession of 14 queens of Irrisen.