In the NSW Supreme Court on Thursday Justice Ian Harrison said Mrs Cullen's death at the hands of her husband was a tragic example of the "malignant cycle of domestic violence" which, despite widespread publicity, does not appear to be abating in society.

Justice Harrison said Cullen, 52, had not expressed remorse nor contrition for murdering Mrs Cullen, 39 in a "ferocious and sustained attack" using two fishing knives.

"I am satisfied beyond reasonable doubt that Mr Cullen intended to kill the deceased," he said.

Mrs Cullen was found slumped forward face down in a kneeling position with her arms in front of her and her head on the ground. She sustained several stab and slicing wounds to her body and throat as well as blunt force injuries.

Cullen did not deny killing his wife and pleaded guilty to manslaughter, but the plea was not accepted by the Crown.

Cullen argued that he had acted in self-defence and had been provoked by his wife.

Following a trial by jury, Cullen was convicted of murder on June 2.

During sentencing submissions, the court heard Cullen had served several prison sentences in his native England for violent crimes, including an assault involving a knuckle duster.

He did not have any convictions in his adopted home of Australia.

The couple married in 2000 and separated in late 2013. Following the marriage breakdown, Mrs Cullen was subjected to violence and threats. Cases were on foot in both the Local and Family courts.

On November 1, 2013 Cullen went to the beauty salon in Sylvania Waters where Mrs Cullen was working and placed signs saying she was sleeping with her clients.

Cullen suspected his wife was in a sexual relationship with another man, and they exchanged heated text messages.

For a short period after she moved out of the family home Mrs Cullen stayed with a man she had met at a Cronulla nightclub, Nick Baastrup.

Ten days later, the police applied for and were granted, a provisional Apprehended Violence Order on behalf of Mrs Cullen.

On the morning of her death, the estranged couple appeared in Sutherland Local Court in a dispute over damage to Cullen's car.

Afterwards, he followed her to her unit block, assaulted her and forced her into the boot of his car.

He drove to the Boating, Camping and Fishing store at Taren Point where he bought two fishing knives.

He then drove to the St George and Sutherland Shire Anglers' Club, where he was a member, and unleashed a "ferocious" and "frenzied" attack.

Police attending the scene heard a moaning and saw Cullen emerge dripping wet from mangroves and suffering self-inflicted stab wounds.

Justice Harrison said Cullen decided to kill Mrs Cullen "for his own selfish and personal reasons; her death was unnecessary, unwarranted, unfair and inexcusable".

Mrs Cullen's death "is another example of the extremely prevalent violence perpetuated by men in our society against women to whom they are married" or in a domestic relationship, he said.

While anger and frustration are common emotions during a relationship breakdown, an "ordinary person in Cullen's position" would not have reacted in such a "violent and unacceptable" way, Justice Harrison said.

Cullen was sentenced to a maximum of 30 years in jail with a non-parole period of 22 years and six months.

With time served he will be eligible for parole in January 2036.

Cullen showed no emotion as he was led away from the dock.

Outside the court, Christina Arciuli, Mrs Cullen's close friend and boss at the Sylvania Waters beauty salon where she worked, said: "It's a great result.

"Her family will have at least some solice in this today," Ms Arciuli said.