 Regardless of whether Pope Pius IX had been personally involved in the decision to remove Mortara from his parents — whether he had been or not was debated extensively in the press — what is certain is that he was greatly surprised by the international furore that erupted over the matter, and promptly adopted the position that to return the baptised child to his non-Christian family would be totally incompatible with Church doctrine. As foreign governments and the various branches of the Rothschild family one by one condemned his actions, Pius IX stood firm on what he saw as a matter of principle. Those angered included Emperor Napoleon III of France, who found the situation particularly vexing as the pontifical government owed its very existence to the French garrison in Rome. Napoleon III had indifferently supported the Pope's temporal rule because it enjoyed widespread support among French Catholics; the scandal over Mortara weakened this considerably and, according to the historian Roger Aubert, provided the final straw that changed French policy. In February 1859 Napoleon III concluded a secret pact with the Kingdom of Sardinia pledging French military support for a campaign to drive the Austrians out and unify Italy — most of the pontifical domain would be absorbed along with the Two Sicilies and other minor states.
