Pope

The Pope was the anointed leader of the Catholic Church, deriving their authority from their predecessors. (PROSE: The Price of Conviction) The Pope was addressed as Your Holiness. (TV: The Crusade, The Vampires of Venice, Extremis) Additonally, the Pope was known as the Bishop of Rome. (TV: Extremis)

History
Saint Peter was the first Pope. (PROSE: The Price of Conviction)

In 800, Pope Leo III crowned Charlemagne as the leader of the Holy Roman Empire. (PROSE: The Lonely Computer)

In 1045, Benedict IX was pope. She founded the Haereticum and had a relationship with the Doctor. (TV: Extremis)

In 1190, King Richard the Lionheart tried to arrange a marriage between his sister Princess Joanna and his enemy Saladin's brother Saphadin in order to broker peace between the English and the Saracens. Joanna herself, however, refused to do so, telling Richard that the Pope would never permit her marriage to "that infidel". (TV: The Crusade)

In 1511, Julius II was the Pope. (AUDIO: Fallen Angels)

In 1887, Pope Leo XIII employed Sherlock Holmes to locate missing books from the Library of St John the Beheaded. (PROSE: All-Consuming Fire)

In 1968, Pope Paul VI complained when the symbol of the Revolution Man appeared in St Peter's Cathedral. (PROSE: Revolution Man)

In 1981, someone tried to assassinate the Pope in St Peter's Square. (PROSE: The Assassin's Story)

In 2008, when Maria Jackson claimed that the Bubble Shock! factory was being run by aliens, Kelsey Hooper sarcastically stated that everyone was an alien, including the Pope. (TV: Invasion of the Bane)

In 2097, an unnamed female Pope made a papal visit to Mars in order to anoint the first Martian bishops. This was done to improve relations between Martians and humans. The Daleks made an assassination attempt. (PROSE: The Gallifrey Chronicles)

In the 27th century, Imogen Tantry became the 314th Pope, taking the name "Beatrix II". (PROSE: Predating the Predators, De Umbris Idearum)

In the 28th century, Pope John Paul XXIII was placed in suspended animation after his death. Celestine VI and Urban IX were rival popes. (PROSE: Companion Piece)

In 3278, according to the Fourth Doctor, the official papal seat of the Catholic Church was situated in the Betelgeuse system. Instead, Lucian was the Pope of the Catholic Church Apostolic in the fictional Europa. (PROSE: Managra)

In the 46th century, the Pope was a clone of St. Peter. He had been grown from one of St. Peter's fingernails. (PROSE: Paydirt)

The Morestran Orthodox Church was led by a Pope. (PROSE: Zeta Major)

The Doctor had advised Pope Clement on the contents of the Vatican Library. (PROSE: Timewyrm: Apocalypse)

In a simulated timeline created by the Monks, the Pope came to St Luke's University and asked the Twelfth Doctor for help. (TV: Extremis)

According to River Song, one Pope was an alien. (AUDIO: The Doomsday Chronometer)