Corlos, son of Caster
Corlos is a figure from the Age of Heroes and the first lord of House Casterly, who took their name from Corlos’ father, a dude called Caster. According to legend, Corlos was a huntsman who lived in a village near to where Lannisport would eventually stand. When a lion began preying on the village’s sheep, Corlos tracked it back to its den, a cave in the base of the Rock. Armed with only a spear, he slew the lion and his mate, but spared the newborn cubs. This act of mercy so pleased the old gods that they sent a sudden ray of sunlight deep into the cave, revealing the gleam of yellow gold in a vein as thick as a man’s waist.
Maester Yandel, a scholar from the Citadel in Oldtown believes he soon moved inside the cave and fortified its entrance and as centuries passed, his descendants delved deeper and deeper into the earth to mine the gold but also carving halls, galleries and tunnels, transforming the gigantic Rock to a castle that dwarfed every other seat in Westeros.