Ravana was born to the sage known as Vishrava. His mother was the Asura princess Kaikesi. Kaikesi's father, Sumali wished her to marry the most powerful being in the mortal world, so as to produce an exceptional heir. He rejected the kings of the world, as their power was less than his. Kaikesi searched among the sages, and finally chose Vishrava. Vishrava warned her that as she approached him at an inappropriate time, their children would be evil, but accepted her nevertheless. So, Ravana was partly Asura, and partly Brahmin.