Concerns over Pope Francis' health have mounted in recent years as have questions about his succession. Here's what we know.

As Pope Francis undergoes treatment for double pneumonia, many are looking ahead to the process of selecting his successor which has remained largely unchanged for the past 800 years

As Pope Francis continues to recover from bronchitis in hospital, many have begun to wonder what the process would be if he were to step down on health grounds like his predecessor, Pope Benedict XVI.