In historical narratives of the Tudor Period, disquisitions on the papal deposing power usually occur as comments on the events of the year 1570, when Pius V issued the Bull Regnans in Excelsis, declaring Queen Elizabeth to be a usurper. Catholic opinion on the deposing power, however, underwent many fluctuations and changes of emphasis in the years that followed. It may be profitable, therefore, to trace the history of the ideas of the English Catholics about the temporal power of the Pope during the seventy years which followed Regnans in Excelsis. In the present article we shall follow the changes as they are reflected in the printed books of those years, and documentary evidence will only be adduced to explain and comment on published statements.