Benjamin John Brennan, 38, entered a caravan next to where he was staying in Narrabundah on March 23, 2011, just before the first anniversary of his premature baby's death.

Brennan, who claimed he was trying to resolve a neighbourhood dispute, tried to punch the man.

The pair traded blows before the offender overpowered his victim and sat on his chest.

He tied his hands, ankles and neck using electrical cord, and demanded money and car keys.

The victim told him to take both, and Brennan then stuffed a face washer in his mouth, using a belt to hold it in place.

Then the man's wife came home.

Brennan knocked her to the ground, blaming the husband for “involving her”.

He demanded the PINs for bank cards, which the husband readily gave over in the hope of protecting his wife.

Brennan took a wallet, phone, gift cards, and cash and left for a short time.

Then, in a move described as “gratuitous and irrational”, he came back, armed with a 30cm serrated knife.

Despite the pleas of his victims, he launched a ferocious attack on the woman as her husband watched, using the knife, a metal picket, and a wheel brace.

She was left with horrific injuries – 50 in total - including 20 lacerations to her face, fractures to her nose, skull and jaw, partial scalping, smashed teeth, and the severance of her little finger.

She required resuscitation and was in a coma for two weeks.

The woman has needed plates, screws, and wires in her face, realignment of her eyeballs, and now has permanent scarring and disfigurement, which made looking in the mirror a struggle.

Brennan left the scene, promising to call an ambulance for the woman, and asking where he could find petrol to help burn the caravan down.

The attacker did neither, and the husband loosened the cables and managed to call help.

Brennan used one of the bank cards to withdraw cash, filled up the stolen car with petrol, and then started driving north, away from Canberra.

He was arrested in Goulburn in the early hours of the next day, and has been in custody since.

The attack left the woman with lasting psychological issues, from post-traumatic stress disorder, to social phobia, sleep problems, and hyper vigilance.

Her husband, who was forced to watch on helplessly, was also damaged psychologically.

“Every day it's in my head, like a re-run of a movie,” he said in a victim impact statement.

He said his wife has unremembered nightmares, in which she cried in her sleep and called out for help.

In the Supreme Court on Monday, Justice Hilary Penfold said the woman had shown “astounding bravery”.

The victim declined an offer to read out her victim impact statement in a room separate to Brennan last month, choosing to give her evidence in his presence.

Brennan had a troubled upbringing.

He said he was sexually abused, beaten, and rejected by his mother at a young age. He did not finish year 10, and began abusing alcohol and drugs.

Brennan was severely affected by the death of his premature baby roughly a year before the offence.

He told the court he cannot explain why he carried out the attack, and described what he had done as “disgusting and barbaric”.

"It's a terrible thing I did and I'm sorry," Brennan said last month.

“I can only hope [the victims] can find some sort of peace in the sentence I get,” he said.

The 38-year-old says he has no memory of the attack, and has not been able to bring himself to read police documents detailing his actions.

Brennan will be eligible for parole in March 2019.

The victims and their friends and family were in court for the sentencing, and clapped and called out as the prison term was handed down.