Nadia Murad was only 22 when the terrorists invaded her village in northern Iraq in 2014 and she was taken into captivity, along with 6,500 other women.
Her mum and six brothers were killed as the ISIS fighters advanced.
Nadia was enslaved, repeatedly raped, told what to wear and made to change her religion.
Children from her village were taken to training camps to become the next generation of ISIS soldiers.
Nadia eventually escaped, fled to Germany and has since become a United Nations goodwill ambassador.
She said: "All ISIS members have the same behaviour and they were dealing with us at the same level, but this one who took me told me he was a very, very bad man.
"I was subjected to many bad things. In total 12 men raped me."
Nadia escaped when her captor went to buy clothes for her after telling her to prepare to be raped.
Any woman over nine was placed into slavery and ordered to convert to ISIS's branch of Islam.
Nadia was held captive by a man with a wife and family.
She was repeatedly raped and fell unconscious during some of her attacks.
"When he went to the supermarket to bring some clothes, I fled and went to a local house in Mosul where someone gave me a fake ID and from there they helped me relocate."
Nadia eventually made her way to America and was given an audience with Barack Obama.