A "wicked and controlling" man who murdered his "fun-loving, mischievous" five-year-old stepson has been ordered to serve at least 17 years in prison.
Elvis Lee, 34, was found guilty yesterday of murdering Tyler Whelan, five.
Lee admitted he kicked and bit Tyler on the day of his death but denied murder.
The boy's mother, Stephanie Whelan, 27, was found guilty of allowing the boy's death. She will be sentenced next month.
At Cambridge Crown Court on Tuesday, Mr Justice Nicol sentenced him to life with a minimum tariff of 17 and a half years.
He said: "Tyler had been left in your care while his mother took two other children to school.
"His young life was cut tragically short. This has been a tragedy for his father, his mother and the rest of the family."
Michael Borrelli, mitigating, claimed that his client was himself abused as a child and attributed the incident to a loss of temper.
"He lacked a real appreciation as to the consequences of what he did because, despite the treatment he himself had been the victim of, he had never suffered serious injury," he said.
But Mr Borrelli said his client had been cleared of cruelty and neglect allegations and should be sentenced on the basis that this was an isolated attack.
In a statement, Malcolm Newsam, executive director of children's services at Peterborough City Council, said there were "lessons to be learned" following Tyler's death.
He added that these were consistent with previous Ofsted inspections which had found weaknesses in the council's procedures to safeguard children.
Sheila Scott, the council's cabinet member for children's services, expressed regret for the "terrible tragedy".
She said that since last year the council had recruited an extra 25 social workers, reduced workloads and is now completing assessments of all vulnerable children in a "timely fashion".