House Stark of Winterfell is a former Great House of Westeros. It ruled over the vast region known as the North from their seat in Winterfell. It is one of the oldest lines of Westerosi nobility by far, claiming a line of descent stretching back over eight thousand years. Before the Targaryen conquest, as well as during the War of the Five Kings, the leaders of House Stark ruled over the region as the Kings in the North.
After the execution of Lord Eddard Stark in King's Landing following the death of King Robert Baratheon I, the North declared independence, and House Stark's new lord, Robb Stark was declared the new King in the North, and fought to secede from the Seven Kingdoms in what would become the War of the Five Kings.
Their rule in the North seemingly ended after the events of the Red Wedding when House Frey and House Bolton betrayed House Stark after forming a secret alliance with House Lannister, during which Roose Bolton murdered Robb Stark, King in the North. Both the North and Winterfell were taken over by House Bolton, with Roose Bolton becoming the de facto Warden of the North, until the murder of Lord Tywin Lannister at the hands of Tyrion Lannister.
House Stark's sigil is a grey direwolf on a white background, over a green escutcheon. They are one of the few noble Houses whose family motto is not a boast or threat. Instead, the House Stark family motto is a warning, one that, no matter the circumstances, will always be relevant: "Winter Is Coming."