Tromanyth
Tromanyth was the name of the successor kingdom to Estorium in what is now the Free Cities.
After Estorium was devastated by the Illithid War, most of the survivors fled north across the sea. The last prince of the empire, now king with the death of his father in the war, established a new kingdom called Tromanyth in 2199. For nearly five hundred years, Tromanyth was a major power in the region. In 2672, the city of Silverstone was founded as part of a trade alliance between Tromanyth and the dwarven nation of Feldran in the Iron Crags.
Secretly, however, Prince Latham of Tromanyth had turned to the worship of Vecna and begun practicing necromantic experiments within his castle. In 2685 he unleashed a powerful spell that instantly transformed everyone else in the castle into an undead minion of Prince Latham, who immediately used his new army to wage a campaign of slaughter across the kingdom, raising those he killed into undeath to expand his forces. Over the next year Feldran fought back in force, aided by clerics and paladins of Pelor from the city of Edras. Though Silverstone held against the undead menace, Feldran was largely overrun. Prince Latham was ultimately cornered and slain in the midst of a ritual that would have made him a lich, ending both the war and the Estorian royal bloodline.
With no king to rule them, the survivors of Tromanyth declared their autonomy, calling themselves the Free Cities.