James Gunn, from Thurso, attacked the women, who cannot be named for legal reasons, at various Caithness locations between July 1980 and August 2015.
The 54-year-old had pleaded guilty to two charges of rape and two charges of assault earlier this year.
Judge Michael O'Grady said Gunn had a "brazen contempt for women".
The High Court in Edinburgh heard how Gunn raped his first victim on an occasion between July 4 1980 and May 1992.
He also subjected the woman to several beatings during the same time period.
He sexually assaulted his second victim on an occasion between 30 October 2002 and 30 November 2010.
He also repeatedly assaulted the woman on various occasions between October 2002 and August 2015.
Defence advocate Shelagh McCall QC told the court her client accepted responsibility for his actions.
She added: "He is realistic about the disposal in this case."
Passing sentence, Judge O'Grady added: "I have rarely had the misfortune to encounter a man such as you.
"You have a brazen contempt for women. You strike me as being heartless, wicked and dangerous and you will understand that a lengthy custodial sentence is inevitable."
Det Insp Muriel Fuller, of Police Scotland's Domestic Abuse Task Force, said: "James Gunn was controlling and physically and sexually abusive towards his victims. The suffering he inflicted on them over a period of time is deplorable.
"The Domestic Abuse Task Force carried out a protracted inquiry into his offending and I hope his conviction and sentence today demonstrates that Police Scotland will robustly and sensitively investigate domestic abuse related crime no matter the passage of time.
"It is certainly no barrier to justice."
She added: "I would also like to take this opportunity to commend the bravery and courage of his victims who assisted with this inquiry and helped us ensure a conviction was secured.
"Although it does not change anything that happened, I hope that they can take some comfort from the verdict and continue to move forward with their lives."
A "heartless and wicked" man who raped and brutally assaulted two women over a 35-year-period has been jailed for nine years.