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 conclave is a time-honored process conducted in secrecy behind the locked doors of the Vatican’s Sistine Chapel.

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.