The world’s cardinals under the age of 80 will gather to elect the successor of Pope Francis, who died April 21 from a stroke and heart failure. The conclave is scheduled to begin May 7.

Ambrogio Piazzoni, then-vice prefect of the Vatican Library and author of a book on the history of papal elections, distributed a sheet of “some curiosities” about the elections to reporters in 2013, after Pope Benedict announced his resignation and before Pope Francis was elected.

The cardinals who enter the Sistine Chapel May 7 to elect a new pope use smoke signals to communicate with the outside world.

The 135 cardinals eligible to elect the next pope will enter the Sistine Chapel to begin the conclave May 7, the Vatican announced.

The conclave to elect a new pope is scheduled to begin May 7 in the Sistine Chapel at the Vatican.

A list of the U.S. cardinals who are under the age of 80 and eligible to enter the conclave May 7 to elect a new pope.

Members of the College of Cardinals had a chance to take a quick bus tour through Rome on their way to visit the tomb of Pope Francis, who wanted to be buried in a Marian basilica three and a half miles from the Vatican.

Mercy — the cornerstone of Pope Francis’ teaching and ministry — must guide the Catholic Church through its period of mourning and the uncertainty that lies ahead, the Vatican’s second-ranking official said.

The casket bearing the body of Pope Francis made its final journey through the streets of Rome accompanied by applause and shouts of gratitude from thousands of mourners.

More than 160 nations sent delegations April 26, headed by kings and queens, presidents and prime ministers, government officials and ambassadors.