Rand al'Thor is special in that he is the only known soul to be woven out by the Wheel of Time for a specific Rebirth. Although there are other known cases of rebirth (such as Birgitte Silverbow and Gaidal Cain), only Rand al'Thor's rebirth has been predicted. Most think of his soul as being Lews Therin Telamon, a male Aes Sedai from the Age of Legends who gained prominence in the Hall of Servants as the Dragon, the leader of the Forces of Light against the Shadow during the War of Power. This is, of course, why al'Thor is generally known as the Dragon Reborn.

Other evidence is showcased in the prologue to The Eye of the World: Ishamael comments that he and Lews Therin have battled each other since the dawn of mankind countless times, suggesting that the Dragon is a prominent figure every time the War of Power occurs. Rand, however, hears Lews Therin's voice in his head, something that Lews Therin himself may not have experienced during his tenure as the Dragon; it is possible that Lews Therin and Rand are more strongly connected than were any previous forms of the Dragon.



Text from Wikipedia