War in Heaven

The War was a large scale time war fought between Time Lords and a loose coalition between Faction Paradox, the Remote, and the Enemy. (PROSE: Alien Bodies, Interference - Book One, Interference - Book Two, The Ancestor Cell) 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 first War in Heaven was considered to have been the hostilities between the Time Lords and the Great Vampires/Yssgaroth (PROSE: The Book of the War).

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. (PROSE: The Ancestor Cell) 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. She planned to use Bull-TARDISes to mate with Compassion to create a new Type 103 TARDIS. (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)

The war begins
As a precaution, the Time Lords created eight clones of Gallifrey with Crypto-forming to create the Nine Homeworlds. The original Gallifrey was named the Homeworld, even though all cloneworlds believed themselves the Homeworld. The Master, who was seen as a more experienced leader, replaced Romana as President. The Time Lords gave him the title of War King because it better suited his duties. The War was started from the original Homeworld itself as the Time Lords realised the true magnitude of the threat they faced. They discovered the Enemy possessed their own Web of Time opposing the Web created by the Time Lords. (PROSE: The Book of the War)

The war began on Dronid. (PROSE: Alien Bodies)

Immediately, the Enemy and the Time Lords attacked each other at many points of space-time. The Enemy attempted a direct attack against the Homeworld itself, which destroyed many Time Lord technologies. (PROSE: The Book of the War)

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 - Book One)

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.

Faction Paradox's stance proved the most opportunistic and changeable. At times they over-ambitiously launched direct attacks on the Time Lords (PROSE: The Book of the War), at times attempted more subtle subversion of their activities (PROSE: Interference - Book One) and eventually found themselves negotiating to be reinstated as a House of Gallifrey. (AUDIO: The Shadow Play)

The Remote were perhaps even more unpredictable; their anarchistic nature utterly committed them to the overthrow of whichever the dominant power was at any given time.

Various Post-human groups allied themselves with the Enemy.

Grandfather Halfling often left the City of the Saved to participate in the War.

From what they assumed was the safe vantage point of non-existence, the Celestis treated the War as a game, sometimes interfering on Gallifrey's behalf and sometimes supplying the Enemy with weaponry. (PROSE: The Book of the War)

Amid the chaos, Gallifrey found time to attack the Osirian Court. Threatening to flood a crucial point in history with vampires, Sutekh effectively blackmailed the Time Lords into a peace treaty (AUDIO: Coming to Dust)

It was suggested that the War was allowed to escalate out of all proportion and the real threat to Gallifrey came from within. (PROSE: Warlords of Utopia) Indeed, the Houses of Gallifey were not above in-fighting, especially the ruling six; Mirraflex, Xianthellipse, Arpexia, Dvora, Tracolix and Lineacrux. (PROSE: The Book of the War) It was House Lolita, though, which most ruthlessly pursued its own interests. (AUDIO: The Shadow Play, In the Year of the Cat)

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)

Segunda Guerra Celestial