Lord of the Dreadfort and head of House Bolton, Roose took pride in his family name and ruthlessly sought its advancement. A proven soldier who fought at the Battle of the Trident, Bolton joined arms with Robb Stark only to betray him at the Red Wedding to gain favor with Tywin Lannister. He broke that alliance when, with Littlefinger, he arranged for his now-legitimate son Ramsay to marry Sansa Stark to solidify his position as Warden of the North. After his new wife Walda gave birth to a trueborn son, Roose and his young family were murdered by Ramsay.
Roose Bolton's new bride, Walda was a granddaughter of Lord Walder Frey. Bolton specifically chose the heavy-set young woman because Lord Walder promised him a dowry equivalent to his wife's weight in silver. After walda gave birth to a son and put Ramsay's birthright ar risk, the bastard murdered the baby, his stepmother and father.
A bastard son of Roose Bolton, the since-legitimized Ramsay captured Theon Greyjoy and tortured him until Theon was a shell of his former self and renamed "Reek". Ramsay married Sansa Stark and forced Theon to bear witness to their wedding night. After his stepmother, Walda, bore his father a trueborn son, Ramsay murdered the baby, Walda and Roose, securing his place as Lord of Winterfell. He lost the castle in the Battle of the Bastards and was killed by Sansa Stark.