Demon King, grandson of Prahlada, son of Virochana, married to Vindhyavali.
Though a demon, he was a devotee of Vishnu and granted him the wish for three paces of land, despite a warning. He was deceived and kicked into the netherworld by the third step of the dwarf Avatar of Vishnu, Vamana.
Bali is also called Mahabali, the great Bali. He is a Chiranjivi, a living endlessly one.
For the story of Vamana and Bali visit
http://hindumythologyforgennext.blogspot.com/2012/02/mahabali-and-goddess-lakshmi.html