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

Time-honored rituals, drafted and refined over centuries, allow time for mourning and provide order at a dramatic moment of transition.

Pope Francis, who is in critical condition in hospital battling double pneumonia, rested well throughout the night, the Vatican said on Tuesday. The 88-year-old pope was admitted to Rome's Gemelli hospital on February 14 with a serious respiratory illness that has since triggered other health problems.