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, the secretive election process to elect the next leader of the Roman Catholic Church, commences on Wednesday.

With the conclave underway, PBS News has a live video of the chimney on the Sistine Chapel as the world waits for white smoke that signals a successful vote for a new pontiff.