Hosteen Frey

Ser Hosteen Frey is the sixth son of Walder Frey and the first with his third wife Amarei Crakehall. He is regarded as the fiercest of Walder Frey's brood.

He is part of the Frey force that joins Robb Stark early in the War of the Five Kings. Hosteen is one of the Freys captured at the Battle of the Green Fork and taken to Harrenhal, though ransomed. He is later part of the force at Harrenhal with Roose Bolton. While meeting with Roose after the Battle of the Blackwater, the Freys are worried at the Lannisters success and alliance with the Tyrells. Hosteen Frey says Robb has lost the war and must make peace with the Lannisters. Later the Freys receive news that Robb has broken the marriage pact.

The Freys agree to make peace with Robb if his uncle Edmure Tully, lord of Riverrun, marries one of Walder Frey's daughters Roslin. However Robb, his mother Catelyn, and much of his army are murdered when the Freys and Boltons betray them in what becomes known as the Red Wedding. During the massacre Hosteen stabs Lucas Blackwood dead.

Hosteen and one of his half-brothers, Ser Aenys Frey, command a Frey force of 1400 that goes north with Lord Bolton, who has been made Warden of the North. Hosteen claims he does not fear the cold but loses an ear to frostbite. Roose orders the Northern lords to attend the wedding of his son Ramsay Bolton to "Arya Stark" (really Jeyne Poole), which is intended to legitimize Bolton rule of the North. However tensions grow in Winterfell due to a series of murders. The three Freys that were travelling from White Harbor, Ser Jared Frey, Symond Frey and Rhaegar Frey, disappear on the way. White Harbor's lord Wyman Manderly, who lost a son at the Red Wedding, has apparently made peace with the Iron Throne. However he is really plotting to restore the Starks to rule of the North. He serves three pies at the wedding to the Boltons and Freys, which possibly contain the missing Freys. Hosteen suspects Wyman of the murders. When Little Walder Frey, the son of Hosteen's full brother Merrett Frey, is found dead Hosteen accuses Wyman. When they insult the Freys Hosteen wounds Manderly and is only prevented from killing him by the intervention of White Harbor men. Seeing the tensions between the Frey and Manderly forces, Roose sends them out to battle Stannis, having received his location in a map sent by Arnolf Karstark.

The Freys leave by the main gate of Winterfell. Meanwhile Theon Greyjoy helps Jeyne Poole escape by jumping with her off the walls of Winterfell. They survive due to the deep snow and are found by Mors Umber, who has joined Stannis. Aenys Frey falls into a pit dug by Mors Umber's troops, breaking his neck. Hosteen loses his horse but survives, command of the Frey force falling to him. Theon relates this news to Stannis and says Hosteen will be angry now, Stannis smiling on hearing this. He says anger makes men stupid and Hosteen was stupid to begin with, nicknaming them Ser Stupid. He implies he has a plan to defeat the Freys. It is possible Stannis' plan is to trick the Freys into charging onto a frozen lake.