This thesis studies the Papal Aggression in England, which was the zealous reaction to a papal decree that had created territorial hierarchy for English Roman Catholics. The study seeks answers to the following questions: Why did the pope create the heirarchy? Why did the English people react so vehemently? Why did Lord John Russell write his Durham Letter? Why did the government fail to enforce the Ecclesiastical Titles Act? What light, if any, does this episode shed on the zeitgeist of the Victorian Age?