One of the most interesting characters in The Lord of the Rings: The Rings of Power was King Durin III who refused to help the Elves to the point of turning his back on his own son. Interestingly, Peter Mullan confirms that he agrees with the Dwarf's decision to leave the Elves to their deaths.
In The Rings of Power, the Elf Elrond discovers that the ore mithril can counteract the fading power of the Elves in Middle-earth. With the help of Prince Durin IV, they try to convince the prince's father to allow them to mine for mithril in the mines of Khazad-dûm.
King Durin III firmly refuses and when the two are discovered mining in secret, Elrond is banished while Durin IV is stripped of his royal status.
Peter Mullan Defends King Durin III's Decision in The Rings of Power
It may have been a selfish decision but Peter Mullan confirmed with Collider that he agrees with King Durin III.
"I absolutely agree with that decision. They’re boring as all hell, and kill the Elves!" Merrell joked. "That comes from the Dwarf. King Dwarf says the Elves deserve everything they get."
"They're too big, literally and metaphorically. Get rid!" Merrell added.
If you know anything about The Lord of the Rings, it's safe to say that King Durin III was right all along. After all, a Balrog lives deep below that mithril mine and it should remain sealed in order to save the Dwarves.
Although King Durin made the right call in the first season, there's a huge chance that things will change in The Rings of Power Season 2. Mullan had previously teased that there will be more rings in the second season and one of those rings could be gifted to King Durin III.
“There are more rings; the show is called The Rings of Power. Maybe I’ll be getting a new necklace, who knows?” he said.
In J.R.R. Tolkien's works, King Durin III is one of the Dwarves to receive a ring during the Second Age. It is yet unknown whether the ring is the one that influences Durin to reopen the mine to dig for more mithril.
The Lord of the Rings: The Rings of Power Season 2 has not yet been given an official release date.