The ancestral home of the Lannisters is Casterly Rock, an ancient stronghold located in Lannisport in the westerlands. Often referred to simply as the Rock, the stronghold was originally built as a ringfort; over the years, the ringfort expanded until it became an impregnable fortress. As of Game of Thrones, Casterly Rock is roughly two leagues in length and three times the height of the Wall. In addition to the watchtowers from its historic days, full of tunnels, dungeons, storerooms, barracks, halls, stables, courtyards, gardens, prison cells, and rooms that once housed lions. The Rock even has a seaport to the Sunset Sea. The sea comes in below the rock, creating a thunder-like noise, and deep in the bowels of the stronghold are the famed gold mines.
With such a home, it’s no wonder the Lannisters are as proud as they are. But the Rock didn’t always belong to the Lannisters. The Rock was originally built by a family called the Casterlys, from whom it gets its name. So what happened to them?