1878 conclave
| Papal conclave February 1878 | |
|---|---|
| Dates and location | |
| 18–20 February 1878 Sistine Chapel, Apostolic Palace, Vatican Hill, Rome | |
| Key officials | |
| Dean | Luigi di San Filippo e Sorso |
| Sub-dean | Camillo di Pietro |
| Camerlengo | Gioacchino Pecci |
| Protopriest | Josef von Schwarzenberg |
| Protodeacon | Prospero Caterini |
| Secretary | Pietro Lasagni |
| Election | |
| Electors | 61 (3 absentees) |
| Ballots | 3 |
| Elected pope | |
| Gioacchino Pecci Name taken: Leo XIII | |
A papal 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 eligible cardinal electors, all but three attended. On the third ballot, the conclave elected Cardinal Gioacchino Pecci, the camerlengo of the Apostolic Chamber and archbishop-bishop of Perugia. After accepting his election, he took the name Leo XIII.
It was the first election of a pope who would not rule the Papal States and the first to meet in the Apostolic Palace in the Vatican, since the venue used earlier in the 19th century, the Quirinal Palace, was now the palace of the king of Italy, Umberto I.