All Vatican elections
May 15551565–1566

1559 Conclave

elected Pius IV

5 September – 25 December 1559 · The early modern conclaves · Cappella Paolina, Apostolic Palace, Papal States

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.

Elected pope

Pius IV

Giovanni Medici

Succeeded

Paul IV

Duration

4 months

Cardinal electors

—

locked in under conclave rules

Key officials

DeanJean du Bellay
CamerlengoGuido Ascanio Sforza

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.