NEW YORK -- "Game of Thrones" rules.

On the heels of its explosive fourth season premiere, HBO has renewed the epic fantasy series for two more years. The network promised more "dazzling storytelling" in those fifth and sixth seasons.

Based on the bestselling book series by George R.R. Martin, "Game of Thrones" is set on the exotic, often war-torn continent of Westeros. Cast regulars include Peter Dinklage, Lena Headey, Charles Dance and Natalie Dormer.

Sunday's season debut was seen by 6.6 million viewers, making it HBO's most-watched program since the finale of "The Sopranos" in 2007. Its audience was 50 per cent larger than for last season's premiere.