Sealing of Ussag, Lord of the Storm Giants

Early Civilizations discovered many things when moving north, most notably native Giants. The ones considered most dangerous of these native Giants were the Storm Giants, though research years later found they were peaceful. Wanting to make the land safer for future they gathered the most magic-able of their people and banded together to trap the Lord of Giants, Ussag, within the earth, successfully guessing that without their leader the roaming bands of Giants will leave.