A "wicked and controlling" man who murdered his "fun-loving, mischievous" 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 kick was so hard that Tyler flew two feet through the air hitting a door at his home in Sheepwalk, Paston, near Peterborough, rupturing his abdomen and slowly killing him.
At Cambridge Crown Court today, 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.
"Tyler was particularly vulnerable because of his age. He was only half your height and a quarter of your weight.
"I entertain the lingering suspicion you inflicted more blows than you have admitted and that may have been the reason Tyler said nothing to his mother when she returned."
The boy's mother, Stephanie Whelan, 27, was found guilty of allowing the boy's death. She will be sentenced next month.
A report published after the conviction found that key opportunities to protect Tyler were missed by authorities tasked with his care.
It acknowledged that previous incidents in which the boy was hurt had been "seen in isolation" with "minimal attempts to link concerning patterns of injuries".
Michael Borrelli QC, mitigating, said Lee's attack on Tyler on March 7 last year was not pre-meditated and was instead a loss of temper and "act of spite".
He said: "My client was himself the victim of considerable violence as a child.
"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."
The trial heard evidence that Tyler suffered a number of "non-accidental" injuries in the year before his death.
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.