Pope Sergius II

Pope Sergius II (Latin: Sergius II; died 24 January 847) was Pope from January 844 to his death in 847.
On the death of Gregory IV, the archdeacon John was proclaimed pope by popular acclamation, while the nobility elected Sergius, a Roman of noble birth. The opposition was suppressed, with Sergius intervening to save John's life. Sergius was then consecrated immediately by the nobles (or the bishops), without seeking the ratification of the Frankish court.
The Holy Roman Emperor Lothair I, however, disapproved of this abandonment of the Constitutio Romana of 824, which included a statute that no pope should be consecrated until his election had the approval of the Frankish emperor. He sent an army under his son Louis, the recently appointed Viceroy of Italy, to re-establish his authority. The Church and the Emperor reached an accommodation, with Louis being crowned king of Lombardy by Sergius, although the Pope did not accede to all the demands made upon him.
Sergius contributed to urban redevelopment in Rome, relying on what some consider to be dubious means of gaining money. Simony is said to have flourished during the reign of Sergius II.
During his pontificate the ouskirts of Rome were ravaged, and the churches of St. Peter and St. Paul were sacked by Arabs, who also approached Porto and Ostia in August 846. During the raid, he (along with the people of Rome) looked on helplessly as they hid behind the Aurelian walls. Despite having been forewarned of the intentions of the raiders, Sergius is seen as having not acted adequately enough to prepare for that which eventuated.
Sergius died while negotiating between two patriarchs and was succeeded by Pope Leo IV.

Pope Sergius was portrayed by John Goodman in the 2009 film, Pope Joan.