founder of the order of Our Lady of Ransom (Mercedarians, or Nolascans), a religious institute originally designed to ransom Christian captives from the Moors; today, the Mercedarians, whose numbers have declined, are engaged mostly in hospital work.

Peter dedicated himself to helping the poor. In Spain, where the Moors held many Christian slaves gained from struggles between the Moorish and the Christian kingdoms there, he ransomed them with funds from his inheritance and from contributions. Between 1218 and 1234, he founded his order at Barcelona. Peter is said to have gone twice to Africa to redeem Christian slaves there. He resigned his offices of master general and ransomer some years before his death.

When his cause for canonization was being considered in Rome, there was presented a notarial act, the documento de los sellos (“document of the seals”), declaring that the Blessed Virgin Mary came to Peter and instructed him to found his order. The documento has since been proved to be a forgery.