There were three further violent episodes: one in which Boyes "rag-dolled" his then partner so aggressively he ripped a handful of hair from her scalp and another in which he a put her in a "wrestling hold" and attempted to break her legs.
But the worst of it came on Christmas Eve last year.
The couple were hosting a barbecue and Boyes was "spoiling for an argument" because the victim had shared lunch with a friend he disliked.
At 9pm, he began throwing beer bottles at the feet of his ex-girlfriend and other guests, showering them with glass.
Those at the party quickly exited but the ordeal was just beginning for the victim.
After punching a television, Boyes turned his attention to the woman, throwing her around the room and hitting her repeatedly in the head and body.
When she fell to the floor he stomped on her so hard she was unconscious and lost control of her bladder, court documents said.
To "control his anger", the summary said, Boyes then head-butted the wall, knocking himself out too.
When the victim came to, she made for the bathroom in a bid to escape but accidentally kicked the defendant, rousing him from his blackout.
Boyes redoubled his violence, inflicting punches, kicks and stomps against his ex-partner, "at times pulling her arms away so that she could not defend herself".
While she lay on the floor "helpless", he strangled her, rendering her unconscious again.
There was a brief panic when Boyes heard sirens but once he realised they were attending another emergency he ordered the woman to clean up the house and make his dinner.
Once that was done, the court heard, the "hysterical" victim bolted from the property and flagged down a passing vehicle which took her away.
As the woman was being rushed to hospital by a friend, Boyes shredded numerous items of her clothing.
Her list of injuries, which included two black eyes, dozens of bruises and burst blood vessels in her eyeballs, covered more than half a page of the court summary.
Police arrested Boyes in the early hours of Christmas morning when he cast himself as the victim.
After speaking to a lawyer, though, he explained he had "made a big mistake and was very very sorry".
But Judge David Robinson questioned that stance.
Boyes recently told a psychologist some of the charges had been exaggerated and he claimed the victim had added to the crime scene.
What was clear, the judge said, was the defendant had suffered a traumatic upbringing which began with his adoption from Romania. He had sustained head injuries and had diagnosed disorders, which mitigated the offending, he said.
Boyes was jailed for two years seven months. A protection order was issued in favour of the victim.
How to get help
If you're in danger now:
• Phone the police on 111 or ask neighbours or friends to ring for you.
• Run outside and head for where there are other people. Scream for help so your neighbours can hear you.
• Take the children with you. Don't stop to get anything else.
• If you are being abused, remember it's not your fault. Violence is never okay.
Where to go for help or more information:
• Women's Refuge: Crisis line - 0800 REFUGE or 0800 733 843 (available 24/7)
• Shine: Helpline - 0508 744 633 (available 24/7)
• It's Not Ok: Family violence information line - 0800 456 450
• Shakti: Specialist services for African, Asian and Middle Eastern women and children. Crisis line - 0800 742 584 (available 24/7)
• Ministry of Justice: For information on family violence
• Te Kupenga Whakaoti Mahi Patunga: National Network of Family Violence Services
• White Ribbon: Aiming to eliminate men's violence towards women
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