A MAN’S hidden dark side surfaced on a night out with his partner to celebrate his father’s 60th birthday, a court heard.

Robert William Hamilton’s “simmering” anger boiled over in a row over money for the taxi fare home and he launched a ferocious attack on his girlfriend of four months.

Durham Crown Court heard he swore at her, pushed the startled woman to the ground where he then kicked her in the ribs.

When she managed to get to her feet and attempted to run away, he ran up to her and punched her repeatedly, again causing her to slump to the ground.

Realising the severity of what he had done, he tried to resuscitate her, but other, concerned revellers came over and escorted her to a phone box, where they watched over her until police arrived on scene, in Spennymoor town centre.

The victim suffered a broken jaw and lengthy bruising to her side and back.

Hamilton, 30, of Granville Terrace, Binchester, denied a charge of causing grievous bodily harm.

He claimed she came at him in their argument and in self-defence he pushed out at her, causing her to go to the ground, in such a manner that it resulted in her injuries.

But, following a two-day trial, the jury rejected his explanation and returned a unanimous guilty verdict.

The court heard that the victim had to have a plate inserted in her jaw and she has suffered with infections since, which have left her constantly having to take antibiotics.

In her impact statement, read to the court, she said for the first four months of their relationship he had treated her well, but added: “I didn’t see it coming and can’t believe how he changed so much.”

Andrew Finlay, mitigating, said described the incident, on January 14/15 last year, as “out of character”.

He said his client is a self-employed roofer with a good work ethic, with only one non-related offence on his record, dating from his juvenile days.

Jailing him for three years, however, Judge Jonathan Carroll told him: “The drunker you got that night the more boorish and bullying you got.

“Following a completely trivial argument about taxi money you lost control.

“It was a petulant, drunken, yobbish display of behaviour, and completely unprovoked.”