The green men or Green Men is a sacred order entrusted with the guardianship of the Isle of Faces in the riverlands. Some nursery tales claim they are horned and have dark, green skin. According to Old Nan, the green men ride elks and sometimes have antlers. Most maesters believe their clothes are green and they wear headdresses with horns.
After many years of war between the First Men and the children of the forest, their respective wise men came to the conclusion that the bloodshed had gone on too long. They came together to make peace on the Isle of Faces in the Gods Eye, agreeing to the Pact which would give the First Men all the land except for the deep forests, which would remain under the dominion of the children of the forest. The First Men agreed they would cut down no more trees. So that the gods could bear witness to the historic agreement, all the trees on the island would have a face carved into it and the order of the green men would be created to guard them.