Hjalti was a shrewd tactician, and his small band of Colovian troops and Nord berserkers broke the Reachman line, forcing them back beyond the gates of Old Hrol'dan. A siege seemed impossible, as Hjalti could expect no reinforcements from Falkreath. That night a storm came and visited Hjalti's camp. It spoke with him in his tent. At dawn, Hjalti went up to the gates, and the storm followed just above his head. Arrows could not penetrate the winds around him. He shouted down the walls of Old Hrol'dan, and his men poured in. After their victory, the Nords called Hjalti Talos, or Stormcrown.
- The Arcturian Heresy
https://en.uesp.net/wiki/Lore:The_Arcturian_Heresy
Hroldan features in a pivotal piece of Elder Scrolls lore, as a walled, nigh-impregnable fortress of the Reachfolk. In order to unite the Colovian Estates, Culechain, King of Falkreath, needs to secure his northern border, and so sends his general, the soon-to-be Talos to take out this Reachfolk stronghold. Talos employs storm winds to deflect the hail of arrows directed at him, while he uses the power of The Voice to shout down the very walls.
During the events of ESO, we can visit the stone ring that defines this location at this time. By exploring the quest associated with the location, you can discover some interesting Reachfolk customs, and navigate thorny inter-tribal politics.
I don't want to knock ZOS' decisions- I think the story in that location is interesting. But its curious to me that the old, established lore and story associated with this place wasn't capitalised on, or even recognised in any capacity. I think it can be argued that ESO is set some 250 years before its absolute latest possible founding (around the time of its siege by Talos), which leaves the possibility of interpreting the location however they want. But its existence, -or even significance- as a strategic location relative to their age-old conflict with Falkreath and the rest of Skyrim still begs the question of: "why not?"
During the events of the Horns of the Reach story, we're introduced to the enigmatic Gherig Bull Blood and his fierce Dreadhorn Clan. This Meet the Character explores them a little
https://en.uesp.net/wiki/Lore:Meet_the_Character_-_Domihaus_the_Bloody-Horned. This faction is fascinating due to their pact with Minotaurs and their suggested Keptu (Nedic) roots, and the dungeons during which we encounter them remain amongst my favourite for these reasons. While during TES5 Skyrim, there are no Minotaurs in the province at all, they fit so well in the ancient pine forests and rocky canyons of Falkreath and The Reach that we can readily believe that once, they existed pretty organically amongst the other primal beasts of the region.
I think that the Keptu roots, in particular was a fascinating hook, too. Given that the Dreadhorns are seeking "ancestral land" in Falkreath- not traditionally considered as part of the Reach in any source- perhaps the heritage that Gherig is leveraging for legitimate ownership of these lands instead appeals to deeper-Nedic- roots.?
By the time of the Markarth DLC, we get to explore the political landscape of The Reach, but there is no reference to the Dreadhorn Clan; upon completing the dungeons, you've destroyed their leadership structure, and the lands closest to Falkreath Hold are occupied by the Six Ford, Eagleseer and Ghostsong Clans.
I'd still love to know about how other clans relate(d) to the clans we see in Markarth. The Dark Witnesses, the Winterborn and the Dreadhorn clans are all driven off, with their leadership destroyed during the events of ESO. Factions such as the Dreadhorn are really compelling to me, and I think its a shame if that's the end of their story. Surely there could be more to tell?
Given their specific interest in Falkreath in particular, and assuming that they persist in any capacity after the events of HotR, we have a specific identity for particular Reachfolk associated with territorial disputes between Falkreath and The Reach. I think this leaves open the distinct possibility that it is the Dreadhorn clan that will eventually create a powerful stronghold that guards the valley between The Reach and Falkreath. Markarth DLC was a highlight for many people because it cast the Reach clans- traditionally depicted as evil- in a more relatable light. While The Reach story is done for now, we are yet to see Falkreath proper. More could be done with both the Dreadhorn clan, and maybe even Hroldan- in the future. In keeping with the tone of exploring all sides of the conflicts that rack Tamriel, perhaps we could even be required to build a tenuous accord with them, for some mutual objective. Perhaps we could get insight into their plans to build the fortress that will be pivotal to the story of both The Reach and the Empire. Either way, I hope we get to see more of the Dreadhorn clan.