themaesters:

ca.-10,000 - Age of Heroes: An era during the history of Westeros, which would be named so later for the great men and women who live in the years of peace and prosperity following the forging of the Pact. The Pact endures for nearly four thousand years, and in that time, the children of the forest and the First Men grow closer. In time, the First Men set aside many of their cultural differences to embrace the ways and customs of the children of the forest. With the exception of the Drowned God of the Iron Islands and the Lady of the Waves and Lord of the Skies of the Three Sisters, the gods of the children become those of the First Men.

Many of the noble houses of Westeros today trace their lineage back to the Age of Heroes. This was the time when grand historical figures are said to have lived, such as Brandon the Builder, founder of House Stark; Lann the Clever, founder of House Lannister, who winkles Casterly Rock from the Casterlys; or Garth the Gardener, founder of House Gardener of the Reach. Also during this era the Storm Kings of House Durrandon arise in the stormlands—a line with figures such as the founding Durran, supposed builder of Storm’s End—and the Grey King rules the ironborn of the Iron Islands.

ASOIAF + The Timeline of Major Events