Pope Stephen II (715 – 26 April 757) was Pope from 752 to 757, succeeding Pope Zachary following the death of Pope-elect Stephen. Stephen II marks the historical delineation between the Byzantine Papacy and the Frankish Papacy.
Allegiance to Constantinople
The Lombards to the north of Rome had captured Ravenna, capital of the Eastern Roman Empire Exarchate of Ravenna, in 751, and began to put pressure on the city of Rome.
Relations were very strained in the mid-8th century between the papacy and the Eastern Roman emperors over the support of the Isaurian Dynasty for iconoclasm. Likewise, maintaining political control over Rome became untenable as the Eastern Roman Empire itself was beset by the Abbasid Caliphate to the south and Bulgars to the northwest. As a result, Rome was unable to secure military support from Constantinople to push back Lombard forces.
Alliance with the Franks
Stephen turned to Pepin the Younger, the recently-crowned King of the Franks, and even traveled to Paris to plead for help in person. On 6 January 754, Stephen re-consecrated Pepin as king. In return, Pepin assumed the role of ordained protector of the Church and set his sights on the Lombards.
Pepin invaded Italy twice to settle the Lombard problem and delivered the territory between Rome and Ravenna to the papacy, but left the Lombard kings in possession of their kingdom.
Duchy of Rome and the Papal States
Prior to Stephen's alliance with Pepin, Rome had constituted the central city of the Duchy of Rome, which composed one of two districts within the Exarchate of Ravenna, along with Ravenna itself. At Quiercy the Frankish nobles finally gave their consent to a campaign in Lombardy. Roman Catholic tradition asserts that then and there Pepin executed in writing a promise to give to the Church certain territories that were to be wrested from the Lombards, and which would be referred to later as the Papal States. Known as the Donation of Pepin, no actual document has been preserved, but later 8th-century sources quote from it.
Stephen now anointed Pepin at Saint-Denis in a memorable ceremony that was recalled in coronation rites of French kings until the end of the ancien regime in 1789.
In return, in 756, Pepin and his Frankish army forced the last Lombard king to surrender his conquests, and Pepin officially conferred upon the pope the territories belonging to Ravenna, even cities such as Forlì with their hinterlands, laying the Donation of Pepin upon the tomb of Saint Peter, according to traditional later accounts. The gift included Lombard conquests in the Romagna and in the duchies of Spoleto and Benevento, and the Pentapolis in the Marche (the "five cities" of Rimini, Pesaro, Fano, Senigallia and Ancona). For the first time, the Donation made the pope a temporal ruler over a strip of territory that extended diagonally across Italy from the Tyrrhenian to the Adriatic. Over these extensive and mountainous territories the medieval popes were unable to exercise effective sovereignty, given the pressures of the times, and the new Papal States preserved the old Lombard heritage of many small counties and marquisates, each centered upon a fortified rocca.
Pepin confirmed his Donation in Rome in 756, and in 774 Charlemagne confirmed the donation of his father.