A love triangle between staff at a North East tourist attraction ended in bloodshed, a court heard.
Trouble flared after Brett Fenwick had an affair with Louise Pearce, who had been in an 18-year relationship with Gareth Mallaburn.
After cleaner Miss Pearce confessed to cheating on the father of her three children on Bonfire Night, there was tension between the two men in her life, both kitchen workers at Alnwick Garden.
It is alleged that late on Boxing Day night last year, Brett and his brother, Blaine, armed themselves with knives and went to the couple's home.
Prosecutors say they barged into the house and Brett allegedly stabbed Mr Mallaburn in the neck before turning his violence on Miss Pearce.
Brett has pleaded guilty to attempting to murder Miss Pearce but he and Blaine deny wounding with intent on Mr Mallaburn and are standing trial at Newcastle Crown Court.
Mark Giuliani, prosecuting, told jurors: "In the early hours of December 27, while drunk, the defendants went to the home of Louise Pearce and Gareth Mallaburn.
"Each of them were armed with a knife about six inches in length and the Crown's case is they were intending to seriously injure Gareth Mallaburn, who had been the partner of Louise Pearce for 18 years.
"Louise Pearce was at that time having what is best described as an affair with Brett Fenwick.
"The two brothers, drunk and armed with knives, barged their way into their home."
Mr Mallaburn was upstairs and the two brothers allegedly ran up the stairs and tried to force their way into a bedroom, in which Mr Mallaburn tried to barricade himself.
Mr Giuliani said: "He managed to get out but before he could flee the house, he was stabbed in the neck by Brett Fenwick.
"Brett Fenwick then turned his anger towards Louise Pearce who he tried to kill in a drunken rage.
"Louise Pearce and Gareth Mallaburn were each seriously injured in that attack."
Jurors were told Mr Mallaburn had previously considered Brett Fenwick a friend but he admitted being angry and shocked at the affair revelation and sending some threatening texts to Brett.
Miss Pearce moved out for a time but they got back together and decided to try to repair their relationship.
Mr Giuliani said matters came to a "violent head" in the early hours of December 27 after Miss Pearce returned to the family home on Howling Lane, Alnwick, after a night out with friends.
The Fenwick brothers had also been out drinking when they allegedly decided to go the the family home armed with knives and prosecutors said they would not have known the three children were at their grandparent's home that night.
Prosecutors said they were "loud, drunken and rowdy" outside the house and were shouting aggressively and Brett allegedly said: "Get down here now and we will fight like men".
They banged on the door and Miss Pearce opened it, at which point they barged in, Mr Giuliani said.
Mr Mallaburn was on the landing at the top of the stairs and Brett, followed by Blaine, ran upstairs shouting 'You b****** I'm going to kill you', the court heard.
Mr Mallaburn barricaded himself into the bedroom as Brett shouted about the text messages his rival had sent, jurors were told.
He felt blows on the door as he leaned on it then saw Brett's foot come through it, Mr Giuliani said.
Realising the door was not going to withstand the attack, Mr Mallaburn armed himself with a shelf to defend himself and went out to confront the brothers, who he managed to push down the stairs.
The court heard he thought the Fenwicks were going to leave and when they started arguing among themselves Mr Mallaburn told them he could only listen to one of them at a time.
Mr Giuliani said: "What happened then was Brett took a knife out again and lunged towards Mr Mallaburn and stabbed him in the neck.
"He pulled away but Brett tried to stab him again saying 'you don't know what I'm capable of, you want me to kill you, I will do it right now'."
Mr Mallaburn managed to escape out of the back door and went to his mum's home.
Mr Giuliani said: "At this point Brett Fenwick turned his violence towards the woman with whom he was having an affair and began shouting at her that she was pathetic and would never leave Mr Mallaburn.
"Then he began to attack her, he stabbed her. She got outside and the attack continued outside."
A neighbour who saw what happened will describe how Brett "executed a prolonged and vicious attack" on Miss Pearce.
The court heard the Fenwicks deny going to the house armed with knives and Blaine claimed to police they were defending themselves.
Mr Mallaburn told jurors he had socialised with Brett Fenwick before the affair and said he was "meant to be a friend".
Asked about his reaction to finding out he had been seeing his partner, he said: "I was hurt by the affair, gutted.
"I was angry and just really shocked. Words can't really describe how I felt."
He added: "Louise said she was sorry and had made a mistake.
"She was showered with gifts and lies."
Asked about the texts he sent to Brett, he explained: "Louise had been a big part of my life for about half of my life and to have someone try to take that away from me, I'm going to be angry.
"I suppose I was trying to frighten him to stay away so he didn't have any more contact."
Brett Fenwick, 36, of Lower Barresdale, Alnwick, denies wounding with intent and having a bladed article and Blaine Fenwick, 25, also of Lower Barresdale, Alnwick, denied wounding with intent and two counts of having a bladed article.
The trial continues