| Papal conclave September–December 1559 | |
|---|---|
| Dates and location | |
| 5 September – 25 December 1559 Cappella Paolina, Apostolic Palace, Papal States | |
| Key officials | |
| Dean | Jean du Bellay |
| Sub-dean | François de Tournon |
| Camerlengo | Guido Ascanio Sforza di Santa Fiora |
| Protopriest | Robert de Lenoncourt |
| Protodeacon | Alessandro Farnese |
| Elected pope | |
| Giovanni Angelo Medici Name taken: Pius IV | |
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The 1559 papal conclave (5 September – 25 December) was convened on the death of Pope Paul IV and elected Pope Pius IV as his successor. Due to interference from secular rulers and the cardinals' disregard for their supposed isolation from the outside world, it was the longest conclave of the 16th century.