Pius IX

Giovanni Maria Mastai Ferretti was born at Senigallia on 13 May 1792, became archbishop of Spoleto and then bishop of Imola, and was elected pope on 16 June 1846 (Holy See, biographical profile of Pius IX). On 8 December 1854 he defined that Mary was preserved from all stain of original sin from the first instant of her conception (Pius IX, Ineffabilis Deus definition). Ten years later he issued a list of eighty condemned propositions, the last of which is that the Roman pontiff ought to reconcile himself with progress, liberalism and modern civilization (Pius IX, Syllabus of Errors prop. 80).

He presided in person at the session of 18 July 1870 at which the First Vatican Council defined papal infallibility, and confirmed the decree (Manning, True Story of the Vatican Council pp. 144–145). See the First Vatican Council. Rome fell on 20 September 1870, and with it the temporal power; the Holy See’s account says that he thereafter considered himself a prisoner of the Vatican (Holy See, biographical profile of Pius IX). He died on 7 February 1878 (Holy See, biographical profile of Pius IX).