Time war

 ''This article is about the concept of a time war in general. For the Time War involving the Daleks that resulted in the near-extinction of the Time Lords, see Last Great Time War.'' 

A time war could be one of at least two types of time-spanning conflicts. The first type of time war was where sides fought each other across different points in history. The second type of time war was one in which time itself was used as a weapon by two or more time-active factions, employing preemptive strikes, time loops, temporal paradoxes and the reversal of historical events. It is difficult to study these wars, since they tended to erase the damage before it was made.

The first time war fought by Gallifrey was the Black Sun War, starting when the Order of the Black Sun sent a time-travelling assassin to prevent Gallifrey from gaining time travel. (COMIC: Star Death) The Order itself existed 30,000 years in the future, and launched a second attack twenty years later. (4-D War) The Time Lords had been viewed by the Order as striking first in the present, thanks to a Sontaran scheme. (COMIC: Black Sun Rising)

A second war, lasting thirty thousand years, took place a generation after the time of Rassilon. It was fought between the Time Lords and other races that were developing time travel. The Time Lords destroyed one such race, the Charon, before they even existed. (PROSE: Sky Pirates!)

At one point in the Doctor's future, a war was fought between the Time Lords and the Enemy (who had no other known name). Gallifrey destroyed as a result of the Eighth Doctor attempting to prevent the war from beginning, (PROSE: The Ancestor Cell) though was seemingly restored later on in the Doctor's eighth life. The Time Lords fought against the Daleks in the Last Great Time War, which all thirteen incarnations of the Doctor ended by freezing Gallifrey in a pocket universe, making the Daleks accidentally destroy one another and it appearing to the rest of the universe that the Time Lords and the Daleks had destroyed each other. (TV: The Day of the Doctor)

Behind the scenes

 * The Doctor Who Annual 2006 describes two other time wars - one between the Halldons and the Eternals and the "brutal slaughter" of the Omnicraven Uprising; on both occasions, the Time Lords eventually stepped in to settle matters.