From the Glossary of The Wheel of Time

Occasionally men claim to be the Dragon Reborn, and sometimes one of them gains following enough to require an army to put it down. Some have begun wars that involved many nations. Over the centuries most have been men unable to channel the One Power, but a few could. All, however, either disappeared or were captured and killed, without fulfilling any of the prophecies concerning the Rebirth of The Dragon. These men are called false Dragons.