"Original Gallifrey" because the phrase "Gallifrey Original" is only used in Doctor Who and the Time War, whereas multiple other sources use "original Homeworld" (or "original homeworld" (The Book of the War, Alien Bodies ect)
Talk about it here.
Due to the construction of many duplicates of Gallifrey during the War, the nature and specific fate of the original Homeworld, (PROSE: The Book of the War) termed Gallifrey Original by one account, (PROSE: Doctor Who and the Time War) was a matter of contention and speculation.
History[]
Possible candidates during the War[]
The War King's Homeworld was believed by The Book of the War to be the original, despite the fact it was not located at the original coordinates, (PROSE: "The Nine Homeworlds" [+]Part of The Book of the War, Lawrence Miles, et al., Faction Paradox novels (Mad Norwegian Press, 2002).,"The War King" [+]Part of The Book of the War, Lawrence Miles, et al., Faction Paradox novels (Mad Norwegian Press, 2002).) where Romana III's Gallifrey was. (PROSE: The Shadows of Avalon, The Ancestor Cell) However, The Book of the War did mention that the Houses possessed the "vulgar" technology to move a Homeworld's real-time analogue, and so the original Homeworld not being located at the original coordinates was suggested to be as a means of decieving the Enemy, with it being speculated that the War Queen herself may not be aware her world was a clone. (PROSE: "Modern Time: The Paradox Era" [+]Part of Crimes Against History (second edition), Second edition (2002), Lawrence Miles, The Spiral Politic Database (2001-2002).) However, some accounts treated Romana III's Gallifrey as the original, (PROSE: The Ancestor Cell [+]Peter Anghelides and Stephen Cole, BBC Eighth Doctor Adventures (BBC Books, 2000)., "Modern Time: The Paradox Era" [+]Part of Crimes Against History (second edition), Second edition (2002), Lawrence Miles, The Spiral Politic Database (2001-2002).) which was supported by the fact it was located in Kasterborous, (PROSE: The Ancestor Cell [+]Peter Anghelides and Stephen Cole, BBC Eighth Doctor Adventures (BBC Books, 2000).) the original location of Gallifrey. (TV: Pyramids of Mars [+]Stephen Harris, Doctor Who season 13 (BBC1, 1975).)
Fate[]
Destroyed at the War's end[]
According to one account, at the end of the Last Great Time War, the Eighth Doctor used the Moment to destroy "Gallifrey Original". (PROSE: Doctor Who and the Time War) Similarly, the Eighth Doctor's destruction of Romana III's Gallifrey was seen, by the account which chronicled it, as the destruction of the original Gallifrey. (PROSE: The Ancestor Cell) Various other accounts failing to mention the existence of multiple Gallifreys also indicated it was destroyed. (TV: The End of the World, PROSE: The Eyeless, COMIC: The Forgotten, Sky Jacks)
Destroyed before the War's end[]
According to one account, after the destruction of the original homeworld, Homunculette trained at Gallifrey XII at a time before attending Qixotl's auction. (PROSE: Alien Bodies) Indeed, another account mentioned that "in the future", relative to the 50th year of the War, and after the original Homeworld fell, "the various surviving Homeworlds are in constant contact with each other". (PROSE: Crimes Against History (second edition) [+]Second edition (2002), Lawrence Miles, The Spiral Politic Database (2001-2002).
Survival beyond the War's end[]
Later accounts indicated that Gallifrey survived the War, although they all called it the Last Great Time War rather than War in Heaven, and lacked any indication of other Gallifreys which could possibly call into question the authenticity of the surviving one. (TV: The Day of the Doctor, Hell Bent)
Behind the scenes[]
The first edition of Crimes Against History treated the War Queen's Homeworld as the original, while the second edition had her dropping out of the narrative to be replaced by the War King, with a suggestion that she had gone on to become the President of one of the Nine Gallifreys as part of a ruse to construe one of the Cloneworlds as the original. Although this rumour can be taken at face value, a possible interpretation is that these rumours were spread by the War King himself to spread the belief that the Homeworld under his control was secretly the original despite the blatant fact of the original President — Romana — still ostensibly ruling the original Gallifrey at the original coordinates.