Pope Stephen II

Stephen II became bishop of Rome in 752, a moment when the papacy's long Byzantine tether was fraying and the Lombards were closing in. Facing invasion with no eastern help coming, he crossed the Alps to Paris to ask Pepin the Short for military aid. Pepin agreed, defeated the Lombards, and handed Stephen a gift of conquered territory — the seed of what would grow into the Papal States. It was a pivot: Rome looking west instead of east, the pope becoming not just a spiritual leader but a sovereign. Stephen died in 757, five years into the arrangement that redrew the map.