Warren Jeffs, 51, was convicted of two counts of rape as an accomplice for his role in the marriage of a 14-year-old follower and her 19-year-old cousin in 2001. It will be up to the Utah parole board to decide how long he actually stays behind bars.
Jeffs' attorney, Wally Bugden, asked the judge for concurrent sentences but lost the argument Tuesday.
"This was all about religion," Bugden said outside court. "The foundation of this case was the prosecution of Mr. Jeffs because of placement marriages."
Jeffs is head of the Fundamentalist Church of Jesus Christ of Latter Day Saints, whose members practice polygamy in arranged marriages that have often involved placing young girls with older men. Most FLDS members live in the twin communities of Hildale, Utah, and Colorado City, Arizona, about 350 miles (563 kilometers) southwest of Salt Lake City .
Prosecutors said Jeffs enticed Elissa Wall into marriage and sex against her will by telling her that the relationship was commanded by God and that any refusal would place her salvation at risk.
Prosecutor Ryan Shaum urged the judge to send a message to all religious leaders that they cannot hide behind their position and say, "Hey, I'm just doing my job."
Bugden said arranging the relationship and encouraging the couple to stay together through difficult times "does not constitute accomplice to rape."
"It's just an unjust result and doesn't add up," he said.
Jurors said Wall's age was a major factor in their decision. Under Utah law, a 14-year-old can consent to sex in some circumstances. But it is not considered consensual if a person younger than 18 is enticed by someone at least three years older.
Wall, now 21, testified that Jeffs failed to help her when she protested the marriage and when she later asked for a divorce because she was uncomfortable having sex with Allen Steed.
Steed, now 26, told a different version of events. He said Wall initiated sex and denied that she had cried during their wedding ceremony.
As a victim in the case, Wall had the right to receive $5,000 ( EUR 3,381.8) from Jeffs as restitution, but she declined Tuesday.
"My restitution is knowing that I spoke the truth and that you and the justice system have done your job," she told the judge.
The Utah parole board's first opportunity to review Jeffs' case comes in 2010, although it could decide to wait longer.
The average for Utahns convicted of rape or other first-degree felony sex offenses is seven years, said Jim Hatch, a state parole board spokesman.
The Associated Press does not typically identify people who allege sexual abuse, but Wall has made several public statements about the case using her maiden name. Citing safety concerns, she and her attorneys have declined to disclose her current legal name. Wall was granted an FLDS divorce by Jeffs after she became pregnant with another man's child; she left the faith and is married.
Steed was charged with rape the day after Jeffs' conviction. His case is pending.
The mainstream Mormon church, the Church of Jesus Christ of Latter-day Saints, renounced polygamy more than a century ago, excommunicates members who engage in the practice and disavows any connection with the FLDS church.