Pope Francis's death at the age of 88 means the Catholic Church must choose a new leader. Here's how cardinals elect the next pontiff at the conclave.

The papal conclave will commence in May, when the cardinals will meet at St. Peter's Basilica and pray for the wisdom to select the next pope.

With 135 cardinals eligible to vote, the coming conclave is set to be the largest in the history of the Catholic Church and one of the most unpredictable in decades.