R'hllor

R'hllor, also known as the Lord of Light, the Heart of Fire, the God of Flame and Shadow, is a prominent god in Essos, but has only a few followers in Westeros, where he is more commonly known as the red god. However, this has begun to change in recent years, with King Viserys III Targaryen taking up the faith in recent years. R'hllor's symbol is a fiery heart. Red priests lead prayers to R'hllor at red temples.

Overview
The religion is based on a dualistic, manichean view of the world: R'hllor, the god of light, heat, and life, and R'hllor's antithesis the Great Other, the god of ice and death.They are locked in an eternal struggle over the fate of the world; a struggle that, according the ancient prophecies from the books of Asshai, will only end when Azor Ahai, the messianic figure, returns wielding a flaming sword called Lightbringer, the Red Sword of Heroes, and raises dragons from stone.

R’hllor is also called the Lord of Light, the Heart of Fire, the God of Flame and Shadow. His nemesis, the Great Other, whose name may not be spoken, is known as the Lord of Darkness, the Soul of Ice, the God of Night and Terror.

The red priests of R'hllor associate fire with life. They see shadows as creations of the Lord of Light, who are the servants of light and the children of fire. According to the priestess Melisandre, the Lord of Light cherishes innocent and beautiful people and items, making them the most precious sacrifice.

The religion of the Lord of Light is found primarily in Essos. R'hllor is worshipped in Asshai and red temples can be found in most of the Free Cities. The town of Selhorys, ruled by Volantis, contains a red temple as well. The Temple of the Lord of Light in Volantis is exceptionally large, said to be the greatest in all the world. According to Archmaester Gramyon, it is about three times the size of the Great Sept of Baelor in King's Landing.

There are few followers of the Lord of Light in Westeros. Red priests can be found in Dorne, Dragonstone, King's Landing, and Oldtown.