Eighteen days after Pope Francis last appeared on the balcony of St. Peter's Basilica, his successor -- the 267th pope -- emerged.

Here's how it works, a list of contenders to become the next pope and how many conclaves there have been in the last 100 years.

Cardinals wrapped up their pre-conclave meetings Tuesday, trying to identify a possible new pope who could follow Pope Francis and make the 2,000-year-old Ca