Ruecha Tokputza, 31, groomed children for sex in Australia and Thailand, filmed their abuse and shared it online.
Prosecutors have said his crimes are the most serious case of sex offending in Australia, and District Court Judge Liesl Chapman on Friday called him a predator whose actions were depraved.
She sentenced him to 40 years, three months behind bars, with a non-parole period of 28 years, after he pleaded guilty to 50 charges committed between 2011 and 2018.
“You are a child’s worst nightmare, you are every parent’s horror, you are a menace to the community,” she said.
“Unfortunately there are many like you out there, fortunately you have been caught.”
The majority of Tokputza’s victims lived in Thailand.
Judge Chapman said the youngest was just 15 months old, and Tokputza removed one child’s nappy and abused another while he slept.
She said Tokputza believed he was helping the children by “showering them with love, care and attention”.
“You said you knew what you did was wrong because they were underage, but you never saw yourself as hurting them,” she said.
“You felt you took care of them and they loved you back.”
In addition to the sex offences, police found 251 pornographic videos and 415 videos on Tokputza’s phone — some of which lasted more than 10 minutes.
Judge Chapman said the material was proof that child pornography was “not a victimless crime”.
She said a psychologist had found Tokputza met the full criteria for a pedophilic disorder, and was at a medium to high risk of sexual reoffending.
He will not be eligible for parole until he is in his late 50s.