Gods Old and New
The Faith of the Seven
Brought to Westeros by the Andals, the Faith of the Seven is the primary religion of the continent. Followers believe in a single god with seven different faces. The Faith is intertwined with the government of Westeros, and its clergy often serve the major houses. Female members known as septas work as governesses for highborn families, and the High Septon -- an ordained minister who forsakes his given name when taking office -- is a position of great power in the capital.
The Old Gods
In the lands where the First Men survived the Andal invasion, the gods of nature -- worshipped by the Children of the Forest before men ever arrived on the continent -- are still respected. The gods have no names or temples. Instead, they are worshipped at large red and white weirwood trees decorated with elaborately carved faces. All noble houses were built with "heart trees" at the center of a "godswood," but many have been converted to gardens since the rise of the Faith of the Seven drove the Old Gods out of the south.
The Drowned God
Although worship of the Drowned God is limited to the Iron Islands, this faith is the third largest in Westeros. Its history dates back thousands of years to a time before the Andal Invasion. Followers of the Drowned God believe he brought flame from the sea and that their responsibility is to rape, reave and carve out kingdoms. As tribute, the Ironborn are "drowned" — submerged entirely into water — to commit themselves to the sea… most are successfully resurrected. This practice is overseen by the Drowned Men, the faith's roughly-dressed clergy.
The Lord of Light
The Lord of Light is the predominant deity in Essos, and several of its cities are home to grand temples in his honor. Yet in Westeros, he is still a foreign concept, and thus he and the faith's rituals are viewed with suspicion, as are its converts. Defenders of the Lord of Light are known as Red Priests because of the crimson robes they wear; their symbol is a fiery heart. Red Priests sing prayers each night beseeching the Lord of Light to bring back the dawn: "The night is dark and full of terrors."