Children of the Forest
The Children of the Forest, sometimes referred to simply as the "children" are the original inhabitants of Westeros, who lived alone throughout the continent of Westeros, long before the arrival of the First Men during the Dawn Age.
Much is unknown about the children, They are a mysterious and magical people who have not been seen by humans for thousands of years. Tales describe them as diminutive humanoid creatures, no larger than children at their tallest, dark and beautiful. The giants call them woh dak nag gram little squirrel people. They call themselves in the True Tongue those who sing the songs of the earth .
The children did not use metal, weave cloth or build cities, instead they lived off the land, using stone implements, wearing shirts of woven leaves and bark leg-bindings, they dwelt in caves, crannogs, and hidden tree villages. They were a people with a deep connection to the land.
Legends say the children of the forest were gifted with supernatural powers and magic; having power over the beasts of the wood, the ability to wear an animal’s skin, and the skill to create music so beautiful as to bring tears to the eyes of any who heard it and the greensight ability. It was they who carved the faces on the weirwoods to keep watch over the woods. Altough the Maesters believe that the greensight was not magic, simply another kind of knowledge. They believe that their wisdom had something to do with the faces in the trees  The children of the forest believe that the weirwood trees were were the god and when they died they become part of the godhood.
They were smaller than men with nut-brown skin and large ears, they usually had large golden eyes, but a few had green or red eyes; these had the gift of greensight to be greenseers. They have three fingers and a thumb with sharp black claw instead of nails.
During the Dawn Age, the children populated the entire continent of Westeros, during that time the First Men invaded Westeros, burning of the great weirwoods caused the children to go to war against them. The children wielded obsidian weapons and bows in battle, but also used powerful magic. They shattered the Arm of Dorne, forming the archipelago later known as the Stepstones, but it was not enough to stop the advance of the First Men. Eventually, the war ended in a truce known as the Pact, which was made on the Isle of Faces in the midst of the lake known as God's Eye. The children's greenseers and wood dancers met with the First Men and terms were agreed: the Children retained the standing forests and the First Men were able to settle the open lands. Faces were carved on all the trees of the island to cement the agreement, with the sacred order of green men established to maintain it, and the Pact endured for some four thousand years.
Approximately eight thousand years before Aegon's Landing, during an extended period of winter known as The Long Night, the Children of the Forest joined with the First Men, to fight against the Others in the War for the Dawn. Eventually the Others were driven back into the Lands of Always Winter.
The children of the forest taught the worship of the Old Gods to the First Men, but this was largely supplanted in the South by the Faith of the Seven after the Andal Invasion. Relations between the children and humans grew distant over the years, until they ceased altogether. By the time of Aegon's Landing, humans had not seen the children for thousands of years.
After the War for the Dawn, the First Men and the children of the forest lived in relative peace, but in these years, the children of the forest began their slow withdrawal from the lands of men, retreating deeper into their forests and beyond the Wall.