Pope Gregory IV (; died 25 January 844) was the bishop of Rome and ruler of the Papal States from October 827 to his death. His pontificate was notable for the papacy’s attempts to intervene in the quarrels between Emperor Louis the Pious and his sons. It also saw the breakup of the Carolingian Empire in 843. Rise to papacy The son of a Roman patrician called John, Gregory was apparently an energetic but mild churchman, renowned for his learning. Consecrated a priest during the pontificate of Pope Paschal I, at the time of Pope Valentine’s death in 827, Gregory was the cardinal priest of the Basilica of St Mark in Rome. Like his predecessor, Gregory was nominated by the nobility, and the electors unanimously agreed that he was the most worthy to become the bishop of Rome. They found him at the Basilica of Saints Cosmas and Damian where, despite his protestations, he was taken and installed at the Lateran Palace, after which he was enthroned as pope-elect sometime in October 827. Gregory’s elevation to the papal see is believed to represent a continuation of the attempts to control the local political situation in Rome which had begun during Pope Eugene II’s pontificate. Gregory's consecration was delayed until 29 March 828, when he received notice of the Emperor Louis the Pious’ approval of his election. This delay was enforced by the imperial envoys, who insisted that the Constitution of 824 expressly forbid the consecration of any pope-elect until the emperor had satisfied himself of the validity of the election. It was said that the emperor reprimanded Gregory for attempting to have himself consecrated before receiving the approval of the emperor. Gregory complied with these demands of imperial supremacy, and in 828 and 829, the pope sent embassies to Louis for unspecified discussions. In January 829, Gregory was involved in a dispute with Farfa Abbey over the ownership of local monastic land by the Roman church. In a court run by a bishop and a representative of the emperor, and in the presence of Gregory, Abbot Ingoald of Farfa claimed that the Frankish emperors had granted them the lands, and that Popes Adrian I and Leo III had taken possession of the land illegally. The imperial representative made a ruling in favour of the abbey, and that the lands were to be restored to the monastery. Although Gregory refused to