Old Gods of the Forest

The Old Gods of the Forest are a collection of unnamed spirits and nature gods which are worshipped by many people of the North, and small numbers elsewhere in Westeros. It is the old religion of Westeros, supplanted by the Faith of the Seven which was brought to the continent by the Andals and is now the dominant faith of the continent. Though the two religions have coexisted for more than six thousand years, there is still tension between the most devout adherents of the two faiths.

Worshippers of the Old Gods do not have elaborate ceremonies, hierarchies of priests or large structures of worship like followers of the Faith. Instead they practice quiet contempation in godswoods, small areas of forest centered on heart trees, great weirwood trees with a face carved into the bark. The faith of the Old Gods is personal and less structured than other religions, though some things are proscribed by it (such as kinslaying and incest). Oaths and promises sworn in front of a heart tree are considered binding.

In the books
In the Song of Ice and Fire novels, the Old Gods were originally worshipped by the Children of the Forest for thousands of years before the arrival of the First Men from the east. The Children and their priests, the greenseers, successfully fought the First Men to a standstill and they signed a Pact of mutual peace and cooperation. Over the succeeding four thousand years, the First Men came to worship the Old Gods as well.

After the war against the Others, the Children gradually disappeared from Westeros. The worship of the Old Gods remained strong across Westeros until the invasion of the Andals, who brought the Faith of the Seven with them from the east. The Faith supplanted the worship of the Old Gods in most lands south of the Neck, but it remained strong in the North. After centuries of religious wars and strife, the two religions settled into a - sometimes uneasy - coexistence.