Duke

Duke was an aristocratic title. The female form was Duchess.

Ben Jackson often called Polly Wright "Duchess" due to her upper class breeding. (TV: The War Machines)

In the 12th century Wolvern was the Duke of Trondheim. (PROSE: Dark Horizons)

The Mandragora Helix diverted the TARDIS to [Italy in 1492, where the Fourth Doctor and Sarah Jane Smith met Duke Giuliano. (TV: The Masque of Mandragora)

In the 16th century, Ferdinand was the Duke of Florence. (PROSE: Minions of the Moon)

Torchwood India was run by Eleanor, Duchess of Melrose in the early 20th century. (AUDIO: Golden Age)

By the mid 20th century, Prince Philip was the Duke of Edinburgh. (PROSE: Dance of the Voodoo Valkyries)

The Duke of Forgill was abducted by the Zygons and impersonated by Broton. (TV: Terror of the Zygons)

Orsino and Estella were the Duke and Duchess of Venice in the late 22nd century. After Estella faked her death, Orsino continued to be Duke for the next century. (AUDIO: The Stones of Venice)

In the 30th century, Duke Walid of Callisto and Duke Armand of Europe were rivals for the throne of the Earth Empire after the Divine Empress's assassination. (PROSE: So Vile a Sin)

The Fourth Doctor claimed to have met the Duke of Marlborough. (TV: The Android Invasion)

Guido was the son of a Duke. (PROSE: The Ghosts of N-Space)

Olivia Somerset was the daughter of the Duke of Somerset. (PROSE: Minions of the Moon)

The Duchess was a character in Alice in Wonderland. (PROSE: Timewyrm: Genesys)