On the evening of 23 June 1858, in the central Italian city of Bologna, police of the Papal States, of which Bologna was then part, arrived at the home of a Jewish couple, Salomone (“Momolo”) and Marianna Padovani Mortara, to seize one of their eight children, six-year-old Edgardo, and transport him to Rome to be raised by the Catholic church.
The police had orders from the authorities in Rome, authorised by Pope Pius IX. Church officials had been told that a Catholic servant girl of the Mortaras, Anna Morisi, had baptized Edgardo while he was ill because she feared that he would otherwise die and go to Hell. Under the law of the Papal States, Edgardo’s baptism, even if illegal, was valid, and made him a Christian. Jews could not legally raise a Christian child, even their own. In 1912, in his relation in favor of the beatification of Pope Pius IX, Edgardo himself noted that the laws of the Papal States did not allow Catholics to work in the homes of Jewish families. That law was widely disregarded.
Edgardo was taken to a house for Catholic converts in Rome, maintained by taxes levied on Jews. His parents were not allowed to see him for several weeks, and then not alone. Pius IX took a personal interest in the case, and all appeals to the Church were rebuffed. Church authorities told the Mortaras that they could have Edgardo back if they converted to Catholicism, but they refused.
(From Dawkins’ The God Delusion)