A gang of paedophiles who raped babies, toddlers and pre-school children and streamed the abuse over the internet to other sex abusers across the world have been branded "beyond human instinct and evil" by a judge.
The men preyed on the families of youngsters to gain access to them and, in one case, groomed a mother and father before their baby was born.
Members travelled hundreds of miles to carry out sickening attacks together or used internet streaming to provide real-time encouragement and directions to those abusing victims.
The seven - aged between 31 and 51 and including three convicted sex offenders - were convicted of 29 child sex abuse offences, including conspiracy to rape and the multiple rape of a child aged under 13.
They are John Denham, 50, from Wiltshire, Matthew Stansfield, 35, from Hampshire, Adam Toms, 33, from Somerset, Christopher Knight, 35, from Manchester, Robin Hollyson, 31, from Bedfordshire, David Harsley, 51, from Yorkshire, and Matthew Lisk, 33, from Sussex.
Passing sentence at Bristol Crown Court, Judge Julian Lambert said: "In the worst nightmare, from the very deepest recesses of the mind, at the darkest hour of the night, few can have imagined the terrifying depravity which you men admit.
"What you contemplated and what you did involved the most horrific abuse of a baby and very young children.
"Your thoughts and deeds are beyond human instinct and reason, and are evil beyond rational understanding.
"You men indulged yourselves in some of the most depraved and grossly deviant behaviour imaginable. The depth to which you sank is astounding and highly shocking to all decent people.
"What you did is contrary to all nature and humanity and you each appear to have a chilling tendency to centre the world on yourselves and your depraved desires without regard for the innocent and vulnerable.
"Your conduct is of deep concern to the public and people are outraged at what you have done. What you did provokes tears in many and makes others feel physically sick.
"Given the strength of public feeling I consider that retribution has a very large part to play in the sentencing exercise. This is no case for treatment and rehabilitation outside prison."
The judge continued: "You each made choices. Those choices have proved catastrophic for you personally but that is of slight concern when compared with the devastating impact of your actions on the victims and their families.
"The material you viewed and the urges you excited in each other were matters of choice for you. You sought out the darkest materials on the internet and met in cyberspace to discuss your perverted sexual desires.
"You then planned the most shockingly sordid exploitation of the very young for sexual purposes. Targeting innocent children in that way is utterly abhorrent and is bound to receive condign punishment.
"The degraded and deplorable state into which you have rendered yourselves is pitiful but there is no room for mercy here.
"All sympathy and compassion must be extended to the victims of crime and their families, and not you."
Hollyson received a 24-year prison sentence plus an extension of eight years on licence while Toms was jailed for 12 years plus an extension of four years on licence.
Knight was jailed for 18 years plus an extension of six years on licence and Stansfield received a 10-year prison sentence plus an extension of four years on licence.
Denham was jailed for eight years plus an extension of four years on licence.
Lisk was jailed for four years plus an extension of three years on licence and Harsley was jailed for two years
They were all placed on the sex offenders' register for life, except for Harsley whose length is still to be determined by the judge.
Online chat logs revealed the gang, who lived across the UK, would offer advice on using "date rape" drugs or over-the-counter medication to drowse children and babies.
Known victims of the men include one baby, aged between three and seven months at the time of the abuse, a four-year-old boy and a boy aged between four and five.
In July 2013, Harsley performed a sexual act near a four-year-old boy, while Denham and Lisk watched through a video link to a hotel room at Heathrow Airport.
Hollyson claimed to have repeatedly raped a baby from the age of three months and filmed himself doing so between December 2013 and January 2014. Later that month, Hollyson, Knight and Denham planned to meet to sexually abuse the boy but could not do so as Hollyson was in hospital.
Hollyson, Knight and Stansfield met in February 2014 though it is not clear what happened.
In May 2014, Hollyson, Stansfield and Toms met up to rape and sexually assault the baby, with the incident filmed and shared.
A video from July 2014 shows Hollyson abusing the baby, while logs reveal Hollyson and Stansfield conspired to rape him in July and August 2014.
Hollyson was arrested in September 2014, ending the baby's abuse. Investigators uncovered images of the baby being abused.
In April 2014, Toms administered drugs to a four-year-old boy to allow him and Knight to abuse him. Photographs of this were shared online. The attacks were carefully planned, with defendants driving hundreds of miles to commit their crimes.
The National Crime Agency uncovered the abuse last September after Toms contacted police to admit he had abused a child. Mr Davies said the impact on the victims and their families was "profound and long lasting".
One of the victim's families added: "We would like to thank police, the National Crime Agency and all the other law enforcement agencies involved for their support and handling of what has been a very traumatic and distressing experience for us.
"No family ever wants to find that their child has been the victim of abuse, nor would they ever knowingly put their child at risk.
"As a family we now need to mend - seeing the perpetrators being brought to justice is the first step."