The Dwarves of Skeggaria

Once, the civilizations of dwarvenkind stretched all across Archaios, albeit largely beneath the surface; interconnected by a vast network of tunnels and passages known as the Skeggarian Low Ways.
For a time, it seemed that the Skeggarians would carry on into eternity, much like the mountains that shielded their subterranean homes. But even stone erodes and mountains crumble. For the dwarves, their diminishing was the result of a classic tale.
As they sought to expand their domain even deeper into the earth, they encountered creatures long forgotten by the surface world. Having opened the metaphorical genie's bottle, the dwarves found themselves ill-equipped to combat the Mind Flayers they had freed from the deepest reaches of the Underdark. Suddenly, their crowning achievement, the Low Ways, were turned against them. With no other course of action available to them, the Skeggarian nations sabotaged the sprawling tunnels to deny their enemy the use of them. In so doing, the many realms of the dwarves became largely cut off from one another.
In time, the Illithid scourge waned, and some of the old kingdoms reconnected again, and while the Skeggarian Low Ways still serve as expressways for Underdark travel, they are now a pale shadow of what they once were.
As for the kingdoms themselves, many found themselves opening out to the surface world (sometimes quite literally), like Kal Nerroth of Horizon and Vathkal of Requiem ingratiated themselves into the realms of men and enjoy a brisk trade and spirit of collaboration. Others, like Kal Kadre cling to their isolationist traditions, though even they must rely on the aid of other dwarven states that have friendlier relations with the outer world. 
Throughout Skeggarian (such as it is now) history, order, hierarchy, and tradition were pillars of their society; something that has continued into modern days. For this reason, dwarven scholars often look back and wonder where they went wrong. In hindsight, it is clear that they rushed blindly into an unknown realm and were ill-prepared for what they may unearth. But why? What was the reason for such reckless abandon? Some have come to wonder if there wasn't some outside influence at play. Indeed, many great civilizations across the world crumbled at their apex, almost as if some sort of invisible force was at play that prevented any one faction from ever growing too large...