The Boltons were among the last lords to submit to the kings of the Stark line. Before that time they fought with implacable ferocity against the Kings of Winter as recently as the time not long after Bael the Bard’s death at the Frozen Ford, when a Bolton lord was said to have slain a Stark and wore his skin as a cloak. It is also said that there is still a room in the Dreadfort where the skins of their enemies are displayed.
The current lord of the house is Roose Bolton. After the death of his young son Domeric, his heir is his bastard son Ramsay Snow.
Information about House Bolton that reveals spoilers from the books.