Even for a dwarf of high birth, Blacktooth is notoriously stubborn. He earned his name as a child. When wrestling with his elder brother, he was thrown and one of his front teeth cracked in half. He denied being hurt, continuing to eat rock nuts in sweet pod syrup. He refused to admit to being in any pain, even as his cracked tooth died and turned black. Eventually, tired of looking at his disgusting rotten tooth stump, his mother snuck into his room and held him down so his sister could pull it. He complained that they were worrying over nothing, and that he quite liked his black tooth. So his father, admiring his toughness, gave him a fake tooth made of Obsidian (the most prestigious of stones) for his ninth birthday.
Being the second son of the nephew of the High King, he grew up with fine education and comfort and a high opinion of his worth. He always worked very hard, even when he did not enjoy the subject and had no talent at it, such as playing the Orc-pipe, because he hated to admit to failure.
As he would have to split his fathers cash endowment with his brothers after his passing, and since his father had been obliged to do the same, Blacktooth always knew he would have to find a way to support himself. Any number of respectable means were at hand. Young dwarves in his situation typically served as Sworn Shields to a related ruler, or took up employment in the administration of their holdings, or pursued a career as a scholar. Those more inclined to idleness might opt instead for pursuing a wife of a wealthy family, whose portion of her father's estate would support their children.
But Blacktooth, though a skilled warrior, competent bookkeeper and proficient in the Law, and a respectable match for any heiress, had one great flaw. He chafed at subordination. He never carried out a command from his elders and teachers without first wrangling with them, suggesting a better course of action, or even outright quarrelling. In fairness it should be said his ideas often we're better. But no King wants to argue with his guardsman, nor does he want to employ an overseer who will disregard his orders. No master jurist wants a willful pupil. And while he could certainly charm a lady and her family, anyone can see that no matter what wealth his wife may have, an unemployed Blacktooth would be an infuriating husband, forever second guessing his wife's choices.
For dwarves like Blacktooth, there is really only one option. They must go forth and Strike the Earth. This is what Dwarves call the act of founding a new hold. A dwarf leads a band of boon companions, journeymen of their respective guilds, finds a promising spot, and sets to carving out his own domain. Be it ever so small, he is now a Master, owing homage of course to the High King and usually to an Underking who supports his effort.
Blacktooth has come to Nordland in hopes of doing just this. The North is known to have many mountains and hills, any one of which might abound in riches. And while a trial to his peers, Blacktooth is gracious and just to those of humbler station, and has friend's and admirers in the craft guilds of the Holiest of Mountains. He need only decide where to site his new hall, and what to name it. He has confidence that once begun, he will be joined by ambitious, adventurous dwarves from the Mountainhomes, and that no matter what the challenges might be, he shall reign Under the Mountain somewhere.