Beregrand from a very young age showed his affinity with axes claiming that he had the feel of an axe. Eventually he became part of the warrior caste and spent a substantial amount of money to have smiths craft runes on his axes an action which earned the empathy of other dwarves.
One day Beregrand killed Jegrek, the King of Gundaar in a Proving. Since it wasn't a fight to death, Beregrand was accused of regicide by the Assembly and was exiled to the surface, a punishment which at that time was both uncommon and very fierce. Due to these events, according to the Memories, Gundaar suffered greatly, probably because of the darkspawn threat.
During his time in Gundaar, Beregrand developed impressive skills and along with his intelligence, when he went to the surface, he greatly expanded the naval power of the city states which centuries later would form Antiva. He also taught human smiths, engineers, and other crafters jealously guarded dwarven secrets, an action which made him a traitor to the rest of the dwarves.