A young man beat his girlfriend to death in a vicious attack that left her with massive bruising and multiple fractures all over her body.
Jordan Matthews has gone on trial accused of murdering Xixi Bi who died after suffering numerous injuries caused by dozens of blows inflicted on her by her boyfriend of about 16 months.
At Cardiff Crown Court on Monday, Paul Lewis, QC, prosecuting, said: "In essence the prosecution alleges that the defendant beat Miss Bi to death in her own home and in a vicious, sustained and prolonged attack that he launched upon her."
Matthews, 24, of Ely Road, Cardiff, South Wales, admitted manslaughter in relation to Miss Bi's death but denies murder.
The court heard Matthews called the emergency services at 8.30am on August 19 last year to request an ambulance "ASAP".
Mr Lewis said: "He said to the operator 'well me and her had a bicker last night and I have ADHD and I hit her a few times and we were OK and she was talking to me and we were fine and she fell asleep'."
Matthews told the operator that he had been "really, really horrible" to Miss Bi and that she was now struggling to breathe, that he had done CPR on her and she was responding.
He was crying during the call, which was played in court, and said: "I think I've done something to one of her ribs."
Mr Lewis said paramedics arrived at the Ely Road flat within minutes but Miss Bi was not breathing and had no heart rhythm.
Miss Bi was rushed to University Hospital of Wales where medics were unable to resuscitate her and she was pronounced dead at 9.30am.
The court heard how the pair moved in together shortly after the beginning of their relationship in around April 2015.
Miss Bi, who was born in China, but educated in the UK from the age of 15, was about to return to Cardiff Metropolitan University to retake a masters in international business management at the time of her death
Mr Lewis said the attack was not the first time the 24-year-old had been the victim of violence at the hands of Matthews and that neighbours heard them arguing on numerous occasions.
Mr Lewis said one man "remembers hearing the defendant shouting 'why do you make me do this to you? I don't want to do it but I have got to. One day I am going to kill you'. Then he heard the deceased crying saying 'I'm sorry, I'm sorry'".
The trial continues.
Mr Lewis said a post-mortem examination, carried out by pathologist Dr Derek James, revealed Miss Bi had suffered "numerous and widespread" bruises over her head, face, shoulders, chest, arms and legs, which indicated multiple "blunt impacts" by fist, knee or foot.
Other bruises were caused by a rod or stick-like weapon, he added.
As well as new injuries, which included a broken jaw on the right side of Miss Bi's face and broken ribs, she was also found to have a number of healing injuries, including broken ribs and a fracture on the left side of her jaw.
Mr Lewis said: "The new fractures and massive bruising that Dr James found all over her body were consistent with having been caused in the hours before Miss Bi's death."
He added that it was a "severe assault that involved dozens of impacts".
Miss Bi also had injuries on her hands and forearms, which Mr Lewis said were caused in an attempt to defend herself. She was in cardiac arrest when she arrived at hospital and cause of death was determined to be complications from her numerous injuries.
Jurors were shown computer-generated images of the injuries, which were "effectively across the whole of the body".
Mr Lewis added: "So numerous and extensive were Miss Bi's injuries that the doctors simply could not give an opinion as to the precise number of impacts that she had suffered."
Miss Bi, who the court heard spoke excellent English, French and Spanish, graduated from her undergraduate degree in international hospitality and events management in July 2015 and was accepted onto the Masters course starting in October 2015.
Mr Lewis said her attendance on the course dropped and she missed some deadlines and she was told she would need to resit the year.
She had started a relationship in April 2015 with Matthews, who later told police they had moved in together the day after they met.
Friends of the couple told officers Miss Bi supported Matthews financially, paying for his clothes, food, accommodation and a car.
One said how she noticed Miss Bi had become "quiet, withdrawn and submissive", said Mr Lewis, while neighbours reported hearing the sound of arguing coming from the flat they shared and police were called on April 17 2016, four months before Miss Bi was killed.
Another friend said she saw Miss Bi with a black eye that she had tried to cover using make-up and with swelling to the left side of her face on another occasion.
The court heard Miss Bi spent six days in hospital that May after undergoing surgery for a fractured jaw, which she told doctors was caused by falling down some stairs.
Mr Lewis said: "Dr James said fractures as a result of a fall (are) certainly possible but somewhat unusual."
He added: "We suggest his (Matthew's) fatal attack on her was not the first time he had used violence towards her."
The jury heard messages sent between the pair, which included one where Matthews said to Miss Bi: "F*** you. Stop texting me you worthless piece of shit.
"You never do anything right. I can't be bothered texting you."
In another, the court heard, he said: "I have to hit you repeatedly in the head while screaming at you."
Mr Lewis said Matthews was dominant in the exchanges while Miss Bi was "apologetic and subservient".