Two young brothers, who tortured and sexually abused two other children in England have been locked up for five years.
Mr Justice Keith, the judge sentencing the two brothers at Sheffield Crown Court, described their attacks as "appalling and terrible".
He said: "The fact is this was prolonged, sadistic violence for no reason other than that you got a real kick out of hurting and humiliating them.
"The bottom line for the two of you is that I'm sure you both pose a very high risk of serious harm to others."
The two boys were both sentenced to an indeterminate period in custody, with a minimum of five years.
The brothers showed no emotion as the sentences were passed.
Mr Justice Keith told the boys: "Neither of you need me to tell you how shocking your attack upon (the first 11-year-old boy) was and how appalling and terrible your treatment of (the two other boys) was."
The judge outlined the violence used by the boys in both the main attack on the two boys and the first attack.
He said he would not go into detail about the attack on the two young boys but added: "What it amounted to was torture."
Speaking about the sexual offences committed by the two defendants, the judge said: "I don't think that you got a sexual thrill out of any of that in the same way that robbing them of (the older boy's) pocket money and (the younger boy's) mobile wasn't about gain.
"It was all part of the torture and humiliation you wanted to subject them to.
"By recording parts of what you did on a mobile, you made at least some of this an example of happy slapping."
Speaking about the effect the attack had had on the victims, Mr Justice Keith said: "Their physical and emotional scars will live with them for a long time to come.
"Their relationship with each other has been seriously affected and their parents have been left with a strong sense of guilt which they didn't begin to deserve about whether they could have done more to protect their boys."
The brothers attacked their victimsd in 90 minutes of sustained violence because they were bored and had “nowt to do”, a court had been told.
The brothers, aged 10 and 11 at the time, told police they had only stopped their sadistic assault because their arms had started to ache.
A doctor who examined the most seriously injured boy, who was found barely conscious at the bottom of a ravine, believed he had been close to death.
The 11 year old victim had earlier told his injured nine year old friend “You go, and I’ll just die here”, the court heard.
The boys, who are uncle and nephew, were marched to a more secluded area and were punched, kicked, stamped on and beaten with sticks.
They were strangled, smashed with bricks, forced to eat nettles, stripped naked and forced to sexually abuse each other.
Lumps of a ceramic sink were also dropped onto the head of the older boy.
The court was shown a 20-minute video recording of the two locations where the boys were attacked last April in Edlington, near Doncaster.
During a police interview following his arrest, the older brother was asked why he had attacked and injured the boys.
He replied: "Don't know. 'Cos there were nowt to do." He told police that he had been bored.
Both boys told police they would have continued with the attack if their arms had not started aching.
When the older brother was asked how close he thought he and his brother had come to killing either or both of the boys, he replied perhaps eight or nine, on a scale of one to 10.
The brothers, now aged 11 and 12, had admitted causing grievous bodily harm with intent, but denied attempted murder which the Crown has accepted.
They also pleaded guilty to robbing the boys and intentionally causing a child to engage in sexual activity.
The judge said that pre-sentence and psychiatric reports compiled about the two defendants made "grim reading".
Speaking about their content, he said: "You chose your victims because of their vulnerability and you wanted to assert your dominance over them by (in the older brother's case) the use of aggression, extreme violence and sexual degradation, targeted to inflict maximum pain in order to gain a sense of power and control over their lives.
"(In the case of the younger brother) a wish to control your victims by domination, degradation and inflicting pain for the purpose of your own emotional pleasure."
The judge continued: "The fact that you couldn't care less what happened to (the two boys) was a strong indicator you harm people simply because you want to."
He said the brothers had already shown a "worrying pattern" of offending and bad behaviour.
Mr Justice Keith said the risk of harm posed by the two boys was so high that he could not impose determinate sentences.
The families of the young victims issued a statement through South Yorkshire Police which said they had found the evidence "deeply upsetting".
They said the events of April last year "rocked our lives".
"We have found the last nine months to have been an extremely difficult and testing time," the statement said.
"Hearing the evidence in court during these past three days has also been deeply upsetting for us all.
"However we would like to thank everyone involved in providing support to us during this time."