A woman who was the centre of a sex abuse ring which used children as "sexual play-things" has been jailed for life.
Marie Black, 34, from Norwich, was convicted of 23 offences including rape, conspiracy to rape and inciting a child to engage in sexual activity, following a trial earlier this year.
The charges related to five young children - two boys and three girls - over a ten year period.
Sentencing her at Norwich Crown Court, Judge Nicholas Coleman told Black she would serve at least 24 years.
The judge said: "The case is the most harrowing it has been my misfortune to try. I and the jurors had to listen to the truly gruesome detail of what took place.
"Your conduct towards these children can only be described as utterly depraved - the children were subjected to sexual abuse of the worst kind.
"They were simply passed around like toys."
Black sobbed uncontrollably throughout the sentencing hearing.
Michael Rogers, 46, from Romford, Essex, was found guilty of 14 counts including cruelty, rape and inciting a child to engage in sexual activity.
Jason Adams, 44, from Norwich, was convicted of 13 similar counts.
Rogers was jailed for 24 years while Adams was sentenced to 24 years. The men were made subject to sexual harm prevention orders.
Seven others stood trial but were cleared of all alleged sex offences.
Judge Coleman said: "You, Marie Black, were the constant factor in all of these crimes.
"The offences included adults conspiring to rape children at so-called sex parties.
"You used them for you own, and for others, sexual gratification.
"It amounts to child sexual abuse of the most serious kind."
He added there was evidence the children were taken to other parts of the country where they were "raffled" for abuse by others.
The trial heard that Black was instrumental in abuse against the children in and around Norwich and London.
It included forcing the children to have sex with and in front of one another. On occasions children's toys, such as Barbie dolls, were used in the attacks, the trial heard.
The trio are said to have hidden behind a "veneer of respectability" as they invited other adults to parties where the children were abused and played card games to decide who would abuse which child.
Sarah Elliott QC, mitigating for Black, said her client had been the victim of "very serious" domestic violence at the hands of Adams.
"He was and is a very manipulative man," she added.
She told the court that evidence was found on Rogers' telephone suggesting he was a paedophile who exploited Black.
Ms Elliott added that Black did not have the "intelligence or the wit" to be part of a "clever Machiavellian scheme" to cover up the abuse.
She said that Black had herself been the victim of sexual grooming at the age of 13.
"She was clearly a vulnerable, corrupted woman," Ms Elliott added.
"The impetus for abusing the children comes from Adams and Rogers.
"She was vilified throughout the trial and was blamed by everybody to exculpate themselves."
However, barristers representing Adams and Rogers rejected the notion that they had manipulated her.
Isabella Forshall QC, for Adams, said he had no previous convictions for sexual offences.
She added: "Although Marie Black seeks to transfer the full load of blame onto Mr Adams, one of the counts reflects her as the only participant, so we don't accept it is entirely his fault.
"She is the common denominator between all the offences."
Ann Cotcher QC said Rogers was a "naive" man who had sought to help Black.
She added: "He still maintains his denial of any wrongdoing.
"Whatever he did do, he was not the instigator of sexual and physical abuse.
"Marie Black had abused the children before he was ever on the scene."
Co-defendant Carol Stadler, 59, from Norwich, was found guilty of assault causing actual bodily harm but cleared of nine other charges, including serious sexual assaults.
She will be sentenced later this afternoon.
Six others - Anthony Stadler, 63, Nicola Collins, 36, Andrew Collins, 52, Judith Fuller, 31, Denise Barnes, 43, and Kathleen Adams, 85, all from Norwich - stood trial but were cleared of all counts.