Asajj Ventress was a Dathomirian female who, at various points throughout her life, was a slave, a Jedi Padawan, an assassin of the Sith, a Nightsister and a bounty hunter.
Asajj Ventress was born on Dathomir years before the Clone Wars into a clan of the Nightsisters. She was taken from her clan mother, Mother Talzin and her.
An assassin trained in the ways of the dark side by Count Dooku, Asajj Ventress yearned to be considered a true Sith, but such status wasn't allowed under the Sith's Rule of Two. Ventress fought with twin red-bladed lightsabers, and clashed with Obi-Wan Kenobi and Anakin Skywalker many times.
As an infant from Dathomir, Asajj Ventress was given over to a slaver from Rattatak to spare the rest of the Nightsister tribe from a similar fate. After the slaver.