Roose Bolton was the Lord of the Dreadfort and head of House Bolton. He was known by some as the Leech Lord.
Roose Bolton was one of the key commanders during the War of the Five Kings and an important adviser to Robb Stark. During the war he was known for his calculating actions, and was a key factor in distracting Tywin Lannister long enough for Robb Stark to lift the siege of Riverrun. Roose would also help to reclaim Harrenhal, after Tywin moved his forces from the holding.
During the war, Roose would marry Walda Frey and she would have a son, much to the displeasure of Roose's bastard, Ramsay Bolton. Ramsay had already played a part in the demise of Roose's trueborn son, Domeric and now he attempted it again with this newest addition to House Bolton. Roose, leaning of this quickly took action, and according to all reports "ended his Bastard with sudden ferocity."