Michael Higginbottom, 76, is said to have targeted his victims while they were pupils at the now closed St Joseph's College in Upholland, Lancashire, in the late 1970s and mid-1980s.
Both complainants said they were abused by Higginbottom in his private living quarters at the boarding school for boys aged 12 to 18, Burnley Crown Court heard.
Opening the case, prosecutor David Temkin said: "The boys were not there at the same time. They didn't know each other then. They don't know each other now.
"Despite that, their accounts - if true -demonstrate that they had very similar experiences, at around the same sort of age, in the defendant's private quarters.
"They were both abused by this defendant - regularly, systematically and horrifically. They were both threatened with violence and both were struck with a strap or a belt.
"The prosecution say that the defendant must have thought these boys had not said anything to anyone. However, in recent years each of them came forward independently with their separate but similar allegations and the defendant's past had finally caught up with him."
The court was told the first complainant attended the college in the late 1970s because he had decided to become a priest.
He told police that St Joseph's was a "cold, dark and forbidding place" and for him it was the venue for "mental, physical and sexual abuse".
Higginbottom - a teacher at the college - forced himself "again and again" on the youngster in acts of anal intercourse and also forced the boy to perform oral sex on him on regular occasions, jurors heard.
Mr Temkin said the complainant could not remember exactly how many times the sexual abuse during his time at the college, but was able to tell the police it was "a lot".
The prosecutor said for many years the complainant did not reveal what had happened to him at the college, but in 2013 he told a friend who encouraged him to report these matters to the police.
The second complainant attended St Joseph's in the mid-1980s and he too had wanted to become a priest.
In 2017, he told police that Higginbottom masturbated him on numerous occasions, performed acts of oral sex on him and on one occasion was anally penetrated.
When interviewed, Higginbottom said the allegations made by the first complainant were "total lies" and he had never been attracted to men or to boys.
He said he had been ordained in 1969 aged 25 and had worked at St Joseph's from 1974 to 1987.
The defendant denied any form of sexual contact with the second complainant.
Mr Temkin told the jury they would also hear evidence from three witnesses who were pupils at the seminary at the relevant times which, he said, would reveal a "dark, cruel and sadistic side" to the defendant.
He said: "They will tell you that he seemed to enjoy inflicting pain on his students by various means of physical punishment."
Higginbottom, of West Farm Road, Newcastle, denies five counts of buggery and seven counts of indecent assault.
The trial, estimated to last up to 12 days, continues on Thursday.
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