VATICAN CITY (AP) — One hundred and thirty-three cardinals are sequestering themselves behind the Vatican’s medieval walls for the start of a conclave starting Wednesday to elect a successor to Pope Francis. Here are some things to know about the election of the 267th pontiff of the Catholic Church, which has 1.4 billion faithful across the world.

The papal conclave begins May 7. Here's how cardinals choose the next pope, what to expect and how secretive the process is.