Born to a distinguished family, the son of Anastasius the Illustris.
61st pope after an inter-regnum of five months.
Little is known of his pontificate.
Noted for his generosity to the poor.
During the Lombard invasion, he appealed for military help to General Narses.
Narses lost in the field, and John retreated for several months to the catacombs; when he returned to the Lateran palance, he had the catacombs repaired and made provision for Mass to be celebrated in them.