A man who raped and sexually abused children over a period of 30 years has been jailed for 20 years.
Robert Smith's offences were described as the worst ever before the courts.
Judge Paul Hoffman, at York Crown Court, told Smith, of Scarborough, that if he died in prison it would be "no more than you deserve".
The 65-year-old had pleaded guilty to 42 sex offences, including rape and serious sexual assault against 21 children between 1954 and 1984.
Judge Hoffman told the court that in the law book Thomas' Sentencing Encyclopaedia, there was no case "that's as bad as this one".
He said: "For 30 years you abused the trust placed in you by parents and children alike to use as sexual playthings [the children you abused].
"You dominated these children by your presence and behaviour. They were terrified of you and you abused them through fear."
Smith had shown a "prolonged and insatiable depravity" and his offences were made even more serious by the "sheer scale of wickedness" and "callous regard" for his victims' feelings.
One woman, who was raped by Smith, was so terrified of what would happen if she confronted him that he went on to abuse her children too.
The court heard he had admitted many more sex offences against children to probation officers.
He pleaded guilty to six counts of rape, 26 counts of indecent assault, seven counts of serious sexual assault, two counts of indecency with a child and one count of assault with intent to commit a serious sexual assault.
Many of Smith's victims, who were aged between four and 16, were abused over a number of years and remained traumatised by the abuse, which had resulted in nervous personalities, stammering and stuttering.
As he was led from the court in handcuffs, victims sitting in the packed public gallery shouted "rot in hell" at the defendant.
Judge Hoffman told those in the gallery: "Your outbursts are entirely understandable and I have nothing but sympathy for your suffering."
Outside the court, one of Smith's victims said it would be a "fitting end" for his abuser to die in jail.
Another said: "Justice has been done. It's been a very traumatic experience and we just want to get on with our lives."
Smith was jailed for two years at Hull Crown Court in 1993 for six counts of indecent assault and three counts of gross indecency.
Earlier, in 1987, he was cautioned following allegations of indecent assault by the same victims involved in the counts for which he has now been sentenced.
Speaking outside court, Det Insp Mick Moore, of North Yorkshire Police, said: "I think it was a missed opportunity but I think it's fair to say that, not only have I never been involved in an investigation such as this before, but I don't know anyone else who has."
Smith was arrested in June 2005 when one of his victims contacted police after realising he was living near a school in Scarborough.