A Catholic brotherhood which supplied teachers to a residential school can be held legally responsible for sexual abuse of boys, leading judges have ruled.
Around 170 men are seeking damages after alleging they were abused as children at St William's in Market Weighton, East Yorkshire, and a former head was convicted numerous serious sexual offences, the Supreme Court was told.
A panel of five Supreme Court justices concluded that legal responsibility should be shared between a welfare society which managed the school and a brotherhood which provided teachers.
St William's was founded in 1865 by Catholic benefactors and run locally as a "reformatory school" for boys, Supreme Court justices had been told at a hearing in London.
In 1933, St William's became an approved school for boys convicted of "custodial offences" and in 1973 it became an assisted community home for children in local authority care.
St William's had been managed by the Middlesbrough Diocesan Rescue Society until 1982 then by the Catholic Child Welfare Society (Diocese of Middlesbrough), the Supreme Court - the highest in the UK - was told.
Members of the Institute of the Brothers of the Christian Schools, founded in 1680, had taught at the school alongside lay teachers - and a brother always acted as headmaster, judges heard.
In 1990, the then head had been expelled from the brotherhood after it was discovered that he was "guilty of systematic sexual abuse of boys in his care", said judges.
He had been convicted of "numerous counts of serious sexual offences" against boys over a 20-year period and St William's had closed in the early 1990s, the court heard.
Damages claims had been brought by 170 men who alleged that they had been abused by that former head and by other brothers, said judges.