Holiness

Holiness (oral address Your Holiness) was a form of address used to refer to the Pope. (TV: The Crusade, The Vampires of Venice, Extremis)

Those who were refered to as such included the Pope in 1190, (TV: The Crusade) and the Pope in 2017 of the Shadow World. (TV: Extremis) In addition, an Inspector, having been deceived by the psychic paper, addressed the Eleventh Doctor as "Your Holiness". (TV: The Vampires of Venice)

In Atlantis, King Dalios was addressed as "Your Holiness". After helping overthrow her husband, Queen Galleia introduced him to the council as "His Holiness, the most venerable, Lord Master." (TV: The Time Monster)