For much of the church’s history, the pope’s body was closely associated with the sanctity of his office, as the papal historian Agostino Paravicini Bagliani described in detail in his 1994 book “The Pope’s Body.” Sanctity is often bound up with mystery, and so the head of the church’s health was shrouded in secrecy until the past century.

Pope Francis has spent 18 full days at Rome’s Gemelli hospital recovering from double pneumonia. It’s by far the longest hospitalization of his 12-year papacy.