An unqualified nanny who violently shook a baby in a "moment of madness" has been jailed for four years.
Viktoria Tautz, 34, was responsible for 10-month-old Joshua Paul when he collapsed at his parents' home in Haringey, north London, within half an hour of his mother leaving for work.
The child was rushed to hospital and died in his parents' arms three days later.
The prosecution alleged Tautz "snapped" and caused Joshua's catastrophic brain and spinal injuries through "dangerous and excessive shaking".
Zoe Johnson QC rejected the suggestion he was hurt in a "horsey game", as head wobbling would have been "nowhere near enough" to kill.
But Tautz denied manslaughter and said she never got "angry" or "frustrated" with the baby, who was born 10 weeks early.
A jury deliberated for nearly seven hours to convict her of the charge by a majority of 10 to two.
Mitigating, Bernard Richmond QC highlighted "worrying features" of the case which led to a "moment of madness".
He said: "She was a young woman with a very limited amount of training with a baby who had obviously very difficult needs.
"She was not fully qualified and ultimately her pay reflected her degree of training."
He told the court the defendant, who was paid £3.60 an hour, also lacked "resilience".
Tautz collapsed in tears in the dock as she was sentenced by Mrs Justice McGowan.
Jailing her, the judge said: "You were not in the same position as a teenage mother in the middle of the night on her own trapped in a flat without anyone to help her."
Tautz began working for the family on June 16 2014 after his mother Pearl Paul returned to work.
The defendant had taken a paediatric first aid training course and was paid £3.60 an hour in her first job as a childminder.
In a statement read in court, Ms Paul said her son was happy with Tautz and that she "never saw her lose her temper".
She said he had fluid on the soft spot of his head, had a large head, and that at an outpatient appointment on July 22, doctors told her both of these had increased.
Ms Paul said she was told that if he vomited, stopped eating or fell unconscious, he should be taken straight to hospital.
She said this information had been passed to Tautz.
Joshua's father, Nirmal Vijayan, said doctors told them their son had fluid on his brain and it was being "reviewed and monitored".
At about 8.40am on August 29, Ms Paul left her son "happy and playing" with Tautz in the one-bedroom flat.
At 9.07am, a neighbour called 999 after Tautz dashed from the flat shouting for help, holding Joshua, who was unconscious and not breathing.
Doctors found Joshua had suffered a devastating and "irrecoverable" brain injury and he died at Great Ormond Street Hospital on September 1.
On her arrest, Tautz told police she had played a horse-riding game with Joshua but he had not had any accidents that morning.
Giving evidence through a Hungarian interpreter, Tautz, of Holly Park Road, Barnet, told jurors that her job was to play with Joshua, feed him and change his nappy but she was not allowed to go out of the flat with him.
The parents asked her to leave the dishes so they could see how much he had eaten and log how often she changed his nappy and the condition of his stool, jurors were told.
On the day Joshua was fatally injured, Tautz said she was in her "usual" mood.
She spent 20 minutes with Joshua in the living room before putting him down in his cot for a nap as she did some sewing nearby.
She picked him up because he started crying "very intensively" and his face was red and swollen, Tautz said.
She told jurors: "Then he stopped crying and I thought he was choking so I put him on his belly and tapped his back."
Tautz said Joshua did not appear to be breathing by then and she "got scared" and rushed into the bathroom and tried to make him vomit.
When that did not work, she ran outside with Joshua in her arms to ask for help, Tautz said, adding: "I was absolutely scared. I didn't know what happened to him."
She denied shaking Joshua in an attempt to revive him.
The court heard that Joshua's parents did not want to make a victim impact statement.
Ms Johnson said: "They do not wish to place their thoughts as to the loss of Joshua before the court but perhaps it goes without saying one can only begin to imagine the loss, particularly of a child."
An NSPCC spokeswoman said: "Tautz inflicted appalling injuries on a 10-month-old baby she had been trusted to look after.
"Instead of caring for him and keeping him safe, her actions have robbed a vulnerable young child of his life."
Detective Inspector Ian Lott, of Scotland Yard, said: "This is an extremely tragic case involving the death of a young child, and our thoughts remain with Joshua's parents.
"The jury recognised that Tautz had a part to play in Joshua's death, and we welcome their guilty verdict."