Gallifreyan was a Gallifreyan language used by the Time Lords. There were several forms of written Gallifreyan. By the time of the Doctor, the archaic Old High Gallifreyan language used in the days of Rassilon had changed considerably. (TV: The Five Doctors) TARDISes' translation circuits translated neither Old High Gallifreyan nor Gallifreyan written in the Doctor's time. (TV: The Time of Angels, A Good Man Goes to War)
Old High Gallifreyan
Old High Gallifreyan was the ancient language of the Time Lords. It was not known by many by the Doctor's era. (TV: The Five Doctors) When speaking of the immense power of his ancestors, the Eleventh Doctor stated that Old High Gallifreyan once possessed the power to raise empires and destroy gods. (TV: The Time of Angels)
The written form of Old High Gallifreyan resembled, to human eyes, a mixture of Greek letters and mathematical symbols.
Within the Doctor's rooms on the Gallifrey of one universe, there was a painting of a woman holding a scroll with the words "Death is but a door" written in High Gallifreyan. (PROSE: The Infinity Doctors)
- Two Time Lords looked at an archive of information on the Third Doctor, which displayed a photo and writing in modern Gallifreyan. (TV: Colony in Space)
- A vaguely Arabic-looking script, in a letter written by the Fourth Doctor to warn the High Council of an assassination, was in modern Gallifreyan. (TV: The Deadly Assassin)
- The Seventh Doctor left a calling card for the Supreme Dalek in a script other than English. It appeared to include the Greek characters Theta Sigma (TV: Remembrance of the Daleks), which had been an old nickname of the Doctor's. (TV: The Armageddon Factor)
- A complex system of interlocking circles was used by the Doctor's TARDIS output screens in "coral desktop theme" mode and was seen in the notes that the Doctor scattered around the console room. (TV: Rose onwards)
- Simpler handwritten circles appeared on the Betamax tape used by the Tenth Doctor to trap the Wire. The circular text, since scribbled over, presumably stated the tape's contents. (TV: The Idiot's Lantern)
- The Visionary wrote interlocking circles, which Rassilon and the other Time Lords could understand. One of the words was "Earth." (TV: The End of Time)
- The envelope from the Eleventh Doctor inviting River Song to Lake Silencio, and a page from the 1,103-year-old Eleventh Doctor's TARDIS diary, were written in Circular Gallifreyan. (TV: The Impossible Astronaut)
- Text in circular Gallifreyan was seen carved into the Doctor's cot. (TV: A Good Man Goes to War)
- A blue fire extinguisher that the Eleventh Doctor used on the TARDIS was marked in silver Circular Gallifreyan. (TV: The Angels Take Manhattan)
- The Eleventh Doctor's second TARDIS control room design featured circular Gallifreyan symbols on rotating sections above the main console and time rotor. (TV: The Snowmen)
- The Whisper Men showed Clarence DeMarco a map that he had to memorise in Circular Gallifreyan that they demanded he give to Madame Vastra. (HOMEVID: Clarence and the Whispermen) These were space-time coordinates. (TV: The Name of the Doctor)
Behind the scenes
- The number system in circular Gallifreyan, as seen in the chapter headings of the New Series Adventures, was in base seven.
- The Gallifreyan spoken by the Doctor in Cold Fusion is represented in the text by Greek type: 'Ανδ Ι τυρνεδ αρουνδ ανδ τηεψ ωερε αλλ ωεαρινγ εψεπατχηεσ.' The passage doesn't actually mean anything in Greek, but if transliterated letter-by-letter to English the passage becomes 'And I turned around and they were all wearing eyepatches,' a sly reference to the infamous Eyepatch Story.
- "Old High Gallifreyan": an article by Jon Preddle on Gallifreyan writing as it appeared in the series pre-2005