Gregory V
When Pope Gregory V (996–999) was driven out of Rome, Nilus opposed the usurpation of Philogatos of Piacenza as antipope. According to his disciple and biographer, Bartholomew, in 998 Nilus hastened to Rome to intercede on behalf of a fellow native of Rossano, John Philogathos, who had, against the advice of Nilus, cooperated in an ill-advised scheme of the Roman noble Crescentius to depose the Emperor Otto III's kinsman, Pope Gregory V. Later when Philogathos was tortured and mutilated, Nilus reproached Gregory and the Emperor for this crime, prophesying that "the curse of heaven sooner or later would affect their cruel hearts".