Nineteenth Century
Pope Pius IX (1792–1878)
Longest-reigning pope; defined the Immaculate Conception and convened Vatican I. Pope Pius IX was head of the Catholic Church from 16 June 1846 until his death in February 1878.
Longest-reigning pope; defined the Immaculate Conception and convened Vatican I. Pope Pius IX was head of the Catholic Church from 16 June 1846 until his death in February 1878.