Starting in the Alpha storyline:
As a child Cammy's parents were murdered by Bison. Bison felt pity on Cammy and spared her life. He trained her to become his bodyguard and assassin, and a member of Shadowloo. She also happened to become his lover. At this time she was only 16 years old. Vega happened to be Cammy's "Co-worker". And the two didn't get along very well. Either Vega was jealous of how good looking Cammy was, or the fact that he was jealous that she was Bison's lover instead of him, whatever the case he wanted her dead and set her up to kill her. He didn't succeed. He managed to scar her face and cause her to lose her memory. This happended near a British intelligence facility. And Col. Wolfman of Delta Red found the mentally damaged Cammy and took her in...
The Super Street Fighter 2 storyline:
At age 19 and after being taken in by Col. Wolfman, Cammy was trained by British intelligence and became a member of Delta Red. Col. Wolfman suspected that Cammy was a member of Shadowloo before she lost her memory and decided that she would be the best candiate to enter the Street Fighter competition, in hopes of helping her get some answers about her past, and learning more about Shadowloo. Toward the end of the competition some of Cammy's memories started returning, and after defeating Vega, Cammy went on to fight Bison so she could learn the truth. After defeating him she asked him why, and who set her up. He said "it" was an accident, and was never meant to happen. She continued to ask about her past and Bison, to Cammy's shock, told her that they used to be lovers. Cammy couldn't believe this and the rest of Delta Red told her that Bison had to be lying. Cammy decided to leave because her current life had to be better than the past...
Hopefully with the new Street Fighter Alpha 3, we'll learn more about Cammy and her experience with Shadowloo.
