If you look at the heide weapon descriptions it tells of a time when the kingdom ruled over all.
A thing i noticed was that "Brume" whatever or whoever that was i havent ever seen a mention of aside from its name but the tower is similiar in design to that of Heide so perhaps these towers where like outposts or something of similiar value.
Then when you think of how Vendrick has one of his knight in brume, Ravel is (Fume knight.) And the brass knights are alike a heavier steel form of the old kngiths in heide so i though:
What if Heide was the original kingdom then it was conqoured by the old iron king whom infuses soul into iron making the brass fire knights we see in brume based of the design of the old knights. The old iron king built his kingdom but he left his queen in brume for the purposes of keeping his reign intact in that reigon. His old freind Alonne kept his old thronw and crown from before his teachings gained him power then as he left his former student the king went after him bringing his queen to replace him and to keep charge of this area. Drawing a close and after his return he built a masive iron castle inspired by what he saw at Brume's tower but he failed as his was too large and his kingdom sunk into the ground. After flinging himself into flame his souls began to morph and meld with the earth into the creature we see today in his kingdoms remains. Years later Vendric rise to power and while scouring the land for a place to build his castle he happened upon the dark.. in this place tuned with the dark he found a throne from the iron kings reign a throne of want deep below this old castle built around the flame was the chasm of the abys connected to shulva and their knights as the emerald herald and many others say "Many kingdoms rose and fell in this spot..." leading me to believe all these kingdoms where ages of fire and their falling eventualy while expanding his reach in this age of man Vendrick found Brume tower and he posted his left hand man Ravel or The Raven there to keep watch throughout his banishment much alike the old iron king did to his queen. With this tower where soul infused with iron much alike the giants do with earth they where drawn by the feel of the soul owned by the old iron king thinking vendrick stole this from them as he was the current ruler they waged a war for this ability of wich they lost and Vendrick gained from this war the ablitiy to create golems which he used to guard his throne of want from others. Then at the end of this age and the begining of the curse spreading once more... and you know the rest as we all made the next part writing our stories like all do.
This is just a specilation but i thought it deserved a little notice so posted it. Critism greatly apreciated ^^