Adrian I is elected pope. A popular pope, Adrian's reign will be one of the longest in papal history. Adrian I will preside over the Second Council of Nicea and maintain good relations with secular leaders like Charlemagne.
In fact, Pope Adrian I calls upon Charlemagne's assistance when Italy is invaded by the Lombards under Desiderius. Pope Adrian soon starts dating his documents from the beginning of the reign of Charlemagne instead of according to the reigns of emperors in Constantinople, a change that will stick throughout the Middle Ages.
The chief conflict between Pope Adrian I and Charlemagne will be over iconoclasm: the pope will agree with the bishops in the East that iconoclasts should be excommunicated whereas Charlemagne and his Frankish bishops opposed the veneration of images. Adrian will also be instrumental in combatting the heresy of Adoptionism which will spread through Spain.