War in Heaven

The War was a massive time war fought between Time Lords and a loose coalition between Faction Paradox, the Remote, and the Enemy. (PROSE: Interference)

The Laws of Time weakened during the conflict, allowing events from the War era to interact with those from before its outbreak. (PROSE: Alien Bodies)

Laws of Time
The Laws of Time forbade Gallifrey's present from interacting with its past or future (PROSE: Lungbarrow). Such was the temporal chaos of the War however, that combatants from the War-Era and Time Lords from the pre-War-Era encountered each other more than once.

The Eighth Doctor found himself participating in an auction for his own corpse against Wartime factions who wished to weaponise it. (PROSE: Alien Bodies)

Knowing the War was approaching, the Time Lords created the Nine Gallifreys. Lady President Romana began stockpiling weapons in The Slaughterhouse, a secret arsenal protected by a time eddy. Even at this early stage, Romana had become War Queen and Mistress of the Nine Gallifreys.

Romana was also aware that new TARDISes would be required for the war. She dispatched two of her most trusted agents, Gandar and Cavis, to capture the newly formed Type 102 TARDIS known as Compassion from the Eighth Doctor (PROSE: The Shadows of Avalon).

The knowledge that the Doctor and the Time Lords gathered about the future of the War created many paradoxes around the War's timeline. This caused the timeline to become very weak. The Doctor later discovered that his original TARDIS had survived its presumed destruction and held the original timeline of the universe without the Enemy. The TARDIS was anchored to two timelines at once and was using the energy of the leaking Foreman Universe to keep the original timeline alive. The Doctor, in a final battle with Grandfather Paradox, restored the original timeline. In this timeline, the Doctor would never become Grandfather Paradox, would never be contaminated by Faction Paradox's biodata-altering virus on Dust and the Enemy would never exist to threaten the universe. The restoration of the original timeline destroyed Gallifrey. (PROSE: The Ancestor Cell)

Future history of the war
It was indicated that the Time Lords were losing the War and there were now at least nine clones of Gallifrey. War Looms clogged the atmosphere of at least one of the Gallifreya with biodata soot. These looms produced Gallifreyan soldiers all day and night to provide the Time Lords with fodder for the War. (PROSE: The Taking of Planet 5)

Preemptive strikes
The Time Lords attempted to beat The Enemy with a preemptive strike at The Enemy's homeworld, but not via conventional time travel. The Time Lords built a giant Gallifreyan warship containing The Cold and aimed it at what they believed to be The Enemy's home world: Earth. (PROSE: Interference)

Participants
Although the conflict was primarily between the Time Lords and the Enemy, other powers became heavily involved as they sought to either evade or exploit the War.

Technology and Development
Time Lords from a later stage of the war did not have humanoid form. Only the 'Generals' had totally humanoid forms.

Type 102 TARDISes and War TARDISes were in full use by The War. 102s were used by Time Lord agents whilst War TARDISes were utilised by Time Lords on missions. (PROSE: Alien Bodies, The Taking of Planet 5)