Martyn Lannister

Martyn Lannister is born in 287, the twin of Willem, to Ser Kevan Lannister and Dorna Swyft.

While the two brothers are still children, Lord Gawen Westerling offers his daughter Jeyne in marriage to one of them. Kevan turns the offer down over the Westerling family's tie to House Spicer.

During the War of the Five Kings, Martyn serves in the army Ser Stafford Lannister gathers at Oxcross. When Robb Stark's forces defeat that army, Martyn is among those taken prisoner.

Held at Riverrun, Kevan Lannister weighs marrying him, or his brother Willem, or young Tion Frey, to Sansa Stark, though nothing comes of it while all three remain captive.

Lord Rickard Karstark kills Willem and Tion inside the camp, and Robb Stark, weighed down by guilt over it, fears for Martyn's life and triples his guard. He soon arranges an exchange: Ser Rolph Spicer hands Martyn over to Lannister forces at Golden Tooth, in return for Robett Glover's release at Deep Den.

Years later, with Lord Lancel Lannister set on leaving his wife and his old life to join the Faith Militant, Genna Lannister suggests another way to secure Darry for the family to Ser Jaime Lannister: marrying Martyn, Lancel's younger brother, to Amerei Frey.