Geirrodur was born to the Rock Trolls that lived beneath the ground in Asgard. His father was the master blacksmith and maker of the tribe, and taught Geirrodur all the arts of the trade. When his father died in a war against the Storm Giants, Geirrodur took his father's place. Loki, the god of mischief, helped Geirrodur overthrow the then-current King of the Trolls, Veldemaris. Ever since that day millennia ago, Geirrodur ruled the Trolls, having forged a mystic spear out of uru as a token of power. Among Geirrodur's finest accomplishments during his reign was the design and construction of burrowing machines which, due to the uru metal of their bits and scoops, could dig holes into other dimensions. Geirrodur's machine has even dug a transdimensional tunnel from the caverns of Asgard into the bowels of the Earth. Geirrodur's rule was only once opposed: for a brief time the Troll warrior Ulik usurped the throne. Geirrodur unsuccessfully attempted to conquer Asgard several times.