From Riots to Reform
In 1271, after nearly three years without a pope, frustrated officials in Viterbo locked the cardinals in a palace and removed its roof to force a decision. This event led Pope Gregory X to establish conclave rules in 1274: electors would be secluded cum clave—“with a key.”
The Two-Thirds Rule
Since the Third Lateran Council of 1179, a two-thirds supermajority has been required to elect a pope. In 1621, Pope Gregory XV forbade cardinals from voting for themselves and standardized the use of secret ballots, refining conclave procedures that remain largely intact.
Secrecy and Ritual
Modern conclaves take place in the Sistine Chapel. Electors—cardinals under 80—swear secrecy and vote up to four times daily. If no result is reached after many rounds, runoff ballots occur. Ballots are burned after each vote: black smoke signals no result; white, a new pope.
From Vote to Balcony
Once a candidate accepts election, he chooses a papal name and dons white robes. The senior cardinal deacon then steps onto the balcony of St. Peter’s Basilica to announce Habemus Papam—“We have a Pope.” The new pontiff then gives his first blessing to the world.
In 1271, after nearly three years without a pope, Viterbo’s officials locked cardinals in a palace and removed the roof to force a decision.
Pope Gregory X responded by creating strict conclave rules in 1274, including seclusion until a new pope is chosen…🧵👇 pic.twitter.com/g6UWYlkGxz
— Detective Tiger's Stories (@TigerDetective) April 22, 2025