1878 Conclave
elected Leo XIII18–20 February 1878 · The long nineteenth century · Sistine Chapel, Apostolic Palace, Kingdom of Italy
A conclave was held from 18 to 20 February 1878 to elect a new pope to succeed Pius IX, who had died on 7 February. Of the 64 members of the College of Cardinals, all but three attended.
Elected pope
Leo XIII
Gioacchino Pecci
Succeeded
Pius IX
Duration
3 days
3 ballots
Cardinal electors
61
locked in under conclave rules
Key officials
| Dean | Luigi di San Filippo e Sorso |
| Camerlengo | Gioacchino Pecci |
Ballot-by-ballot tallies are destroyed by design — the paper is burned in the stove whose smoke announces the result — so this entry records what the Church documents: the dates, the electors, the number of ballots where known, and the man who walked out onto the balcony.