[Inziladun]

Nice post, Form.

Originally Posted by Formendacil

Although Thráin I settled in Erebor and found the Arkenstone there, I doubt he called himself "King Under the Mountain"--and if he did, it doesn't seem to have stuck, since his son Thorin I decided that the Grey Mountains were just as good a place to live as Erebor. My analysis of this situation is the Heirs of Durin after the loss of Moria were just as "lost" as Thrór, Thráin II, and Thorin II after the loss of Erebor.

Looking more closely at it, I wonder if the Longbeards, being the people of Durin, might not have been the only Dwarves to have a "king", and maybe that weighed on them all the more heavily when Khazad-dûm, and later Erebor, were lost.

In The Silmarillion, the only Dwarven cities we see are Nogrod and Belegost.
Interestingly, they don't seem to be referred to as "kingdoms", and their leaders not as "kings".

One [pearl] there was as great as a dove's egg....the chieftain of the Dwarves of Belegost prized it above a mountain of wealth.

Of the Sindar

And later, at the Nirnaeth, the dragon Glaurung was wounded by Dwarves, and

in his rage Glaurung turned and struck down Azaghâl, Lord of Belegost.

Of the Fifth Battle

After the sack of Doriath by the Dwarves of Nogrod, and their subsequent ambush in Ossiriand, Beren

himself slew the Lord of Nogrod.

The Dwarves of Nogrod and Belegost, of course, were not of the Longbeards.

In additon, the Ring inscription said "Seven for the Dwarf-lords in their halls of stone."

So, maybe actual Dwarven kingship was reserved for those of the line of Durin, which certainly could have influenced Thorin in not declaring himself king of a relatively small people in the Ered Luin.