Pope Francis on Friday marked one month in the hospital where he is being treated for double pneumonia, with signs in recent days that indicate he is gradually recovering.

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.