Longest papal reign

Longest papal reign
Who
Pius IX
When
07 February 1878

The longest papal reign was that of Pius IX (Italy, b. Giovanni Maria Mastai-Ferretti, 13 May 1792 ), who was Pope for 31 years 236 days between 16 June 18467 February 1878.

St Peter (c. 33-67), the first Pope, is said to have been head of the Church for 34 years although his papacy cannot be dated accurately.