House Prester of Feastfires is an ancient westerlands house sworn to Casterly Rock, their seat set at the westernmost tip of a coastal peninsula where the Sunset Sea breaks against the rocks below Fair Isle. Their blazon, a red ox on ermine, speaks to the stubborn strength that has long defined their character among the lords of the westerlands. In the time of Lady Johanna Lannister, when the Red Kraken Dalton Greyjoy held Fair Isle and raided the western coast with impunity, Lord Prester was given command of a ragtag fleet of fishing boats and cogs assembled at Feastfires for a crossing to retake the island. The venture ended in catastrophe; Prester was lured into an ambush and slain, and his head was sent back to Casterly Rock as a taunt. The house endured, and when Ser Tywin Lannister moved against the rebellious Reynes of Castamere and the Tarbecks of Tarbeck Hall, the Presters were among the first banners to answer his call, their loyalty to the lion unchanged.
At the time of A Game of Thrones, House Prester is held by Lord Garrison Prester of Feastfires, a steady vassal of the Lannisters. It is Garrison's cousin, Ser Forley Prester, who carries the house's name to prominence in the War of the Five Kings. Short and hard, with a bald pate and a grizzled beard, Ser Forley commands the southern camp at the siege of Riverrun under Ser Jaime Lannister, and when Robb Stark destroys the other camps in the Battle of the Camps, Forley withdraws his men in good order, preserving thousands of spears and bows that would otherwise have been lost. He remains among the most capable field commanders in Lannister service through the campaigns that follow.