Westeros

In the Dawn Age, Westeros was inhabited by the fairy-like Children of the Forest. About 12,000 years before the events recounted in A Song of Ice and Fire, the First Men came to Westeros and, after initial fights, reconciled with the Children. They also built the Wall, a giant fortification in the north of the continent protecting the southern districts from the menaces of the northern wilderness and its inhabitants, e.g. the demonic "Others". 4,000 years later, a new tribe of men, the Andals, invaded Westeros and fought both the First Men and the Children of the Forest, finally extinguishing the latter. After centuries of fight, they established six kingdoms in the south, while the north was still held by the First Men. The later immigration of the Rhoynar brought no greater political turmoil, though the southernmost kingdoms were heavily influenced by their customs. Two hundred centuries after the Doom of Valyria[?], Aegon of the House Targaryen, an ancient Valyrian family, subdued the Seven Kingdoms of Westeros. His descendants ruled over Westeros until finally (about twenty years before the events of A Song of Ice and Fire) Robert Baratheon started a rebellion against the "Mad King" Aerys II. and with the help of other houses defeated the Targaryen army and became king himself.

See also : George R. R. Martin