Britain's youngest person convicted of terrorism was sentenced to a minimum of five years in jail for plotting an Islamic State-inspired "massacre" on an Anzac Day parade in Australia.
The boy, nicknamed "the terrorist" by his classmates, was ony 14 when he masterminded the plot to behead police officers at a memorial event in Melbourne, from his bedroom in Blackburn.
He was handed a life sentence at Manchester Crown Court but may be released after five years under the terms of the ruling.
The teenager, now 15, incited alleged Australian jihadist Sevdet Besim to carry out a "major terrorist plot" which had reached its "late stages" before being thwarted by police, Manchester Crown Court heard.
Passing down the sentence judge Justice Saunders said: "Had the authorities not intervened, (the defendant) would have continued to play his part hoping and intending that the outcome would be the deaths of a number of people."
Sue Hemming, head of special crime and counter terrorism at Britain's Crown Prosecution Service, said the planned attack on the national day of mourning for Australia and New Zealand's military dead was "shocking in its brutality and scope."
Besim, 18, is awaiting trial in Australia next year.
The pair exchanged more than 3,000 encrypted messages as they forged the plan, with the defendant — who played the role of "organiser and adviser" — hailing Besim's choice of weapon as "perfect for tearing through throat", jurors heard.
"It is clear that the purpose of this proposed attack was to promote the ideology and agenda of Isis," prosecutor Paul Greaney told the court at a previous hearing, using an alternative acronym for IS.
In custody the defendant admitted that a "a massacre would have occurred" if police had not intervened, boasting that it would have made him "notorious".
The Muslim boy had been radicalised and recruited by IS online and "quickly became a celebrity within the jihadi Twitter community", his lawyer James Pickup said.
Arguing for a lenient sentence, Pickup said the defendant, who pleaded guilty in July to inciting terrorism overseas, accepted his crimes were "barbaric, immoral and wholly wrong".
The teenager became known by classmates as "the terrorist" after praising Osama bin Laden, stating his desire to become a suicide bomber and threatening to behead teachers at his school in Blackburn.
He described the perpetrators of the deadly Charlie Hebdo terror attacks in Paris in January as his "heroes", prosecutors said.
Concerns about his behaviour led to his referral to a counter-extremism programme, but the voluntary scheme later closed his case.
The boy, who cannot be named for legal reasons, is believed to be the youngest person in Britain convicted for planning terrorist attacks.
