Person

Pope Pius IX

1792–1878 · 19th century · Also known as Giovanni Maria Mastai-Ferretti

Pope Pius IX reigned from 1846 to 1878, the longest pontificate in history. Driven briefly from Rome by the revolution of 1848, he lost most of the Papal States to the Kingdom of Italy in 1860 and Rome itself in 1870, after which he called himself a prisoner in the Vatican. He convened the First Vatican Council, which defined papal infallibility.

Pope Pius IX
Image: Public domain · Wikimedia Commons

Mentioned in 2 state histories

Papal StatesRoman Republic (1849)

See also

Cite this entry
APA
The Epoch Institute. (2026). Pope Pius IX. In The Epoch Institute Encyclopedia. https://the-epoch-institute.org/encyclopedia/pope-pius-ix
MLA
“Pope Pius IX.” The Epoch Institute Encyclopedia, The Epoch Institute, 2026, https://the-epoch-institute.org/encyclopedia/pope-pius-ix. Accessed .
Chicago
The Epoch Institute. “Pope Pius IX.” The Epoch Institute Encyclopedia. 2026. https://the-epoch-institute.org/encyclopedia/pope-pius-ix.
Harvard
The Epoch Institute (2026) ‘Pope Pius IX’, The Epoch Institute Encyclopedia. Available at: https://the-epoch-institute.org/encyclopedia/pope-pius-ix (Accessed: ).

Last reviewed October 2026Random entry ↻