George R. R. Martin's A Song of Ice and Fire novels feature a sizable cast of characters. The series follows three interwoven plotlines: a dynastic war for control of Westeros by several families; the rising threat of the superhuman Others beyond Westeros' northern border; and the ambition of Daenerys Targaryen, the exiled heir of the previous ruling dynasty. The Great Houses of Westeros represent the Seven Kingdoms forged across the continent: the North, the Iron Islands, the Vale of Arryn, the Westerlands, the Stormlands, the Reach, and Dorne. A massive Wall of ice and old magic separates the Seven Kingdoms from the largely unmapped area in the most northern portion of the continent.