Pope Adrian I (Latin: Hadrianus I; 700 – 25 December 795) was the bishop of Rome and ruler of the Papal States from 1 February 772 until his death on 25 December 795. Descended from a family of the military aristocracy of Rome known as domini de via Lata, he was the son of Theodore, who died when Hadrian was still very young; he was welcomed by his paternal uncle Theodotus (or Theodatus) consul, dux et primicerius Sanctae Romanae Ecclesiae.
Adrian and his predecessors had to contend with periodic attempts by the Lombards to expand their holdings in Italy at the expense of the papacy. Not receiving any support from Constantinople, the popes looked for help to the Franks. Adrian's tenure saw the culmination of on-going territorial disputes between Charlemagne and his brother Carloman I. The Lombard king Desiderius supported the claims of Carloman's sons to their late father's land, and requested Pope Adrian crown Carloman's sons "Kings of the Franks". When the Pope failed to do so, Desiderius invaded Papal territory and seized the Duchy of the Pentapolis. Charlemagne besieged Pavia and took the Lombard crown for himself. He then restored the Pentapolis to the Papacy as well as some of the captured Lombard territory.