A 10-month-old baby boy died after he was "dangerously and excessively" shaken by a nanny who snapped and lost her temper, a court has heard.
Joshua Paul was being looked after by childminder Viktoria Tautz, 34, at his home in Culross Close, Haringey, north London, on August 29 2014 when he collapsed.
He was rushed to North Middlesex Hospital before being transferred to Great Ormond Street Hospital but died on September 1 in his parents' arms, the Old Bailey heard.
Tautz, of Holly Park Road, Barnet, who will be assisted during her trial by a Hungarian translator, denies one count of manslaughter.
Prosecuting, Zoe Johnson, said that baby Joshua died "because of a head injury that caused bleeding in his brain, bleeding in his eyes and other brain and spinal injuries".
Opening the trial, Ms Johnson told the jury: "On that day, for whatever reason, the prosecution's case is that something snapped in the defendant and for a short while she lost her temper with Joshua and assaulted him, causing all those injuries.
"Her account of what happened whilst she was looking after Joshua does not explain Joshua's various injuries and therefore something else occurred - we suggest a dangerous and excessive shaking of Joshua - which the defendant has not revealed."
Ms Johnson said the evidence "points to Joshua having suffered an abusive traumatic head injury", with "natural disease and other conditions having been excluded as an explanation" for his collapse and "all those various injuries".
Ms Johnson said Tautz was coming to the end of her employment with the family, "clearly loved" baby Joshua and spent "almost two months in quite testing circumstances".
She added: "You will hear from a number of medical experts and a group of these have concluded that Joshua suffered that head injury as a result of being shaken or shaken with an impact to the head.
"The defendant, Ms Tautz, was in sole charge of Joshua at the time of his collapse. She is charged with the manslaughter of Joshua Paul.
"No-one is suggesting that the defendant intended to kill Joshua, or even to cause him really serious harm.
"The prosecution's case is that the defendant dangerously and excessively shook Joshua and therefore she is responsible for his death."
Joshua, who was born around 10 weeks early, was said to have a large head for his age but scans had not shown up anything of concern, Ms Johnson said.
The court heard how he was being monitored in relation to his head size, and how how a cranial ultrasound scan showed slightly dilated ventricles, but no bleeding on the brain or other abnormalities.
Ms Johnson said Tautz began working for the family on June 16 after Joshua's mother returned to work.
She said Joshua's parents had instructed Tautz not to take him out of the one-bedroomed flat, that she should not bathe him and should not open the door to anyone unless she knew who it was.
Tautz was not given a key to the property and had to change her clothes when she arrived at work because she had a kitten at home, the court heard.
Joshua's mother left the baby in the flat with Tautz on August 29 at 8.40am and said he was "happy and playing" at the time.
Tautz, who was arrested on September 5 2014, said in interviews that she had played a "horse riding game" with Joshua but he had not had any accidents and denied that she had shaken him.
London Ambulance Service was called at 9.07am on August 29 by a neighbour after Tautz emerged from the flat shouting for help and holding Joshua, who was unconscious and not breathing.
Paramedics arrived at 9.11am and found the baby boy lying on his back on the hallway floor while Tautz, who was "extremely distressed", was performing mouth-to-mouth resuscitation.
The child minder told medics Joshua had been crying, and that he "shook twice" when she picked him up, before he went floppy and stopped breathing.
A series of medical tests were later conducted at Great Ormond Street Hospital, with CT scans revealing he had "widespread brain swelling" and bleeding on the brain, within the membranes and into the spinal canal.
"The results were all in keeping with a very sick child but did not provide any explanation for Joshua's sudden collapse and those brain and spinal injuries," Ms Johnson told the jury.
Doctors told Joshua's parents on August 30 that their child had suffered "a devastating and irrecoverable brain injury from which he simply would not survive", his brain was not showing signs of activity and his heart "could stop at any time".
He suffered three cardiac arrests at Great Ormond Street Hospital and died at 10.55pm on September 1.
The trial is expected to last up to four weeks.