However, judge Bill Dunlop, QC, told John Walker: "You are classed as a high risk of re-offending and you may never be released."
Walker, 49, battered and abused his terrified victims at properties in Glasgow and Clydebank. One of the victims was pregnant when he attacked her with a pole.
He also pushed another girlfriend into a coal fire before going on to rape a 16-year-old girl - after telling her he had promised her dead dad he would look after her.
He evaded justice for years until a daughter of one of his victims reported him to police in 2012. It sparked an investigation into the abuse, which finally saw Walker appear at the High Court in Glasgow.
In the middle of his trial he admitted to five rape charges and four accusations of assault spanning from 1988 to 2009.