House Marbrand of Ashemark is a noble house of the westerlands, sworn to House Lannister of Casterly Rock. Their seat of Ashemark sits in the hills near the headwaters of the Tumblestone, a defensible holdfast that has served as the Marbrand base of power for centuries. The house traces its founding to the coming of the Andals, when First Men kings such as Tyrion III and Gerold II of the Rock arranged marriages between their bannermen and the most formidable of the Andal warlords. Tradition holds that the house's blazon commemorates the legend of Huron of the Burning Tree, a devout Andal knight said to be one of the first of his people to enter the westerlands; the faithful tell that lightning struck the tree against which he preached even as his enemies closed around him, setting it ablaze and scattering those who would have slain him. The maesters of the Citadel are less credulous, noting that no written record of Huron predates the sigil's first appearance in heraldic rolls, and that the tale has the shape of a device invented to justify a banner rather than a banner designed to honor a deed.
At the opening of A Game of Thrones, House Marbrand is counted among the principal bannermen of Lord Tywin Lannister. Lord Damon Marbrand holds Ashemark, though he is absent from his seat when Tywin's host rides through the westerlands, a castellan standing in his stead. Damon's son and heir, Ser Addam Marbrand, is one of Tywin's most trusted cavalry commanders, having grown close to Ser Jaime Lannister while the two served together as pages at Casterly Rock. The house's ties to the Lannisters run deeper still through blood: Jeyne Marbrand of Ashemark was given in marriage to Lord Tytos Lannister and bore him five children, Tywin among them, while Darlessa Marbrand wed Tytos's third son Tygett. The burning tree above Ashemark is thus wound into the gold and crimson of Casterly Rock in ways that policy alone cannot fully account for.