Mock Ironside, hails from the Iron Hills, East of Lonely Mountain, north-west of Rhûn. He has left his home to seek whatever evil claimed the life of Thorin Oakenshield.

Fairly young for a Dwarf, Mock is just 150 years old (just over 18 in human ages) and he is much skinnier than most dwarves his height, looking indeed a little like a hobbit except for the beard. His skin is dark in complexion, and his wide brimmed hat typical of some miners hats more than soldiers, but his chainmail and plates not to mention his axe and crossbow, hint at the source of his grey hairs.

In TA 2941, the Dwarf lord Dáin II Ironfoot of the Iron Hills led an army of five hundred warriors to the defense of Thorin Oakenshield which then joined in the Battle of the Five Armies and fought valiantly there. After Thorin's death after the battle, the vacant throne of the Lonely Mountain passed to Thorin's cousin and friend Dain who then became its King and the Iron Hills passed out of records afterwards but they may not have been deserted, and it was possible that Dain and his son retained dominion over them.