|"This fire is the very first one. It was given to man by the dragons. We have kept it going for thousands of years."|
|— The Sun Warrior chief to Aang and Zuko.|
The Eternal Flame, according to Sun Warrior tradition, is the first fire ever acquired by humans in history. Given to them by the dragons, it is ancient and sacred to the Sun Warriors and has been kept alight by their civilization for thousands of years. As the Sun Warriors' most prized possession, it is guarded and kept alive at all times.
The flame was given to the Sun Warriors as a gift from the dragons, the original firebenders. Taking a piece of the Eternal Flame to the firebending masters is part of the test of worth for those wishing to learn the true nature of firebending. If deemed worthy, the masters will share the secret with them; if not, the dragons destroy them on the spot.
When Aang and Zuko visited the Sun Warriors' ancient city to uncover the origin of all firebending, they were given the task to take a piece of the flame to the cave of the masters and present it to them. The Sun Warrior chief told them to maintain the flame at a constant temperature, as a small flame would go out, whereas a large flame would burn out of control. As Aang held the fire in his hands, he commented that it felt "like a little heartbeat".
- The Eternal Flame shares similarities with the Olympic Flame. Like the Eternal Flame, the Olympic Flame stays lit for the entire Olympic games and is always fueled and closely monitored.