Romana III's Gallifrey

One duplicate Gallifrey, a sheath echo created during the War in Heaven (PROSE: Alien Bodies, The Story So Far..., The Brakespeare Voyage) in the constellation of Kasterborous, (PROSE: The Ancestor Cell) was ruled by War Queen Romana III (PROSE: The Shadows of Avalon) before being destroyed by the Eighth Doctor during a Faction Paradox invasion. (PROSE: The Ancestor Cell, The Gallifrey Chronicles)

History
According to the Book of Lies, (PROSE: Unnatural History) after President Romana's reconciliation with the Sisterhood of Karn, (PROSE: Lungbarrow) the Great Grey Eminence made a deal with Faction Paradox to undo the changes and restore his preferred order to Gallifrey (PROSE: Unnatural History) by manipulating the timeline of the newly-regenerated Eighth Doctor. (PROSE: The Eight Doctors, Unnatural History) Subsequently, the Eighth Doctor was uncertain if Romana or Flavia was President. (PROSE: Unnatural History)

Like many sheath echoes, (PROSE: The Story So Far...) this Gallifrey thought it was the original and constructed eight cloneworlds. The idea that it was the original was supported by it being located in Kasterborous, (PROSE: The Shadows of Avalon, The Ancestor Cell, The Gallifrey Chronicles) but The Book of the War speculated that the original Homeworld was moved from its original location and replaced with a copy. (PROSE: The Book of the War) Mother and Father saw that the Romana III's Homeworld was only a sheath echo believing itself to be the original. (PROSE: The Story So Far...)

The High Council was made aware of the War through monitoring of the Obverse and the conflict in the Enclave. President Romana regenerated into a body more suitable for war (PROSE: The Shadows of Avalon) and made herself War Queen and Mistress of the Nine Gallifreys. (PROSE: The Ancestor Cell)

In preparation for Gallifrey's "darkest hour", (AUDIO: Luna Romana) Romana began stockpiling weapons in the Slaughterhouse, a secret arsenal protected by a time eddy, (PROSE: The Ancestor Cell) and she cleared whole sections of the planet to start building Battle TARDISes. (AUDIO: Luna Romana) She planned to use Bull-TARDISes to mate with Compassion to create a new Type 103 TARDIS; (PROSE: The Shadows of Avalon) unlike the War King's Homeworld, (PROSE: The Book of the War) Romana's Gallifrey was able to find and capture Compassion. (PROSE: The Shadows of Avalon, The Banquo Legacy)

Shortly before the Event and during Romana's 150th year as President, the Edifice appeared in the sky of this Gallifrey and began sending temporal waves over the planet, making its residents superstitious and agitated. This was followed by Mother Mathara's Faction Paradox invasion of Gallifrey, which resulted in the Eighth Doctor destroying the planet with the Edifice weapons. (PROSE: The Ancestor Cell)

The Tenth Doctor, thinking back to his destruction of Gallifrey at the end of the Last Great Time War, remembered the events of the Eighth Doctor's destruction of Gallifrey to stop the War in Heaven. (PROSE: The Ancestor Cell, The Eyeless)