Throughout the 20th century, only two conclaves lasted up to five days − Pope Pius X's election in 1903 and Pope Pius XI's election in 1922.

The 133 cardinal electors due to choose a successor to the late Pope Francis gathered inside the Vatican's Sistine Chapel on Wednesday, set to launch the secretive, centuries-old ritual known as the conclave to pick a new pontiff.

Catholic cardinals are gathering at the Vatican to elect the successor to Pope Francis, who died on April 21. Voting will take place in the Sistine Chapel, with ballots continuing in succession until any candidate secures two-thirds of the available votes.