
So, starting with year 632. Morglin emerges from the hills, somewhere southward from the present-day Castle Ironfist. He starts building a town that he calls Ironfist.
Here I marked an estimate of where at that point the borders between the kingdoms could have been. Green is ruled by Sorceress Queen Lamanda, blue by the Barbarian Lord Slayer, red by the Warlock Lord Alamar. Yellow is Morglin's movements, white is goblins coming to live in the new town.
I wonder what their capital cities would have been. Perhaps Alamos, Kriegspire and Darkmoor, respectively? Those three castles were old and abandoned at the time of MM6 IIRC.

Year 633: Morglin continues building up town Ironfist. He names the valley Ragnar Valley, and one of the rivers River Morglin. Dwarves come to the town of Ironfist. Morglin builds the Morglin Ironfist Keep.
I wonder if the Morglin Ironfist Keep is the main keep of Castle Ironfist. Sounds likely.
Also, "Ragnar" is totally "Rangar" (ranger?) backwards. And I also just realised that Regna backwards is "anger". Hum.

Year 635: Morglin takes over a Barbarian town and learns about the other kingdoms.
I'm not too sure which town it is, but likely it's either Castle Temper or Free Haven. It is later emphasised that another town was near open sea; so this town probably wasn't near open sea, so Castle Temper fits (it's near a lake, not sea). But the other town could be Silver Cove, and Free Haven is in Bootleg Bay, while Silver Cove is a proper town on the edge of the sea. So that would fit too, but it requires Castle Temper to not exist yet at that date.

Years 636-638: lots of things happen at once.
First, Morglin fights against an enemy hero and wins the battle. Then he takes over another town by the open sea. He splits hits army, with one hero taking a boat. That hero is defeated by a magician (fits nicely with the notion that Sorceress lands are based in and around Mist; by MM6 it's the seat of the High Sorcerer of Enroth).

Next, a great prince of another realm takes Castle Ironfist. (I show him as coming from Sorceress lands, although it might be from Warlock lands too.)

Morglin retakes Castle Ironfist, but while he's busy doing that, he loses the two other towns. (Again not clear to whom; I maximised the number of kingdoms involved.)

More in a bit.