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 loop s , temporal paradox es 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 " , " 4 - D War " ) The Order itself existed 30 , 000 years in the future , and launched a second attack in the Question Hall twenty years after the initial attack . ( COMIC : " 4 - D War " ) The Time Lord s had been viewed by the Order as striking first in the present , after the Sontaran ambassador Brilox used a psy - snare to make the parahuman Millenium assassinate the Black Sun Elder in an attempt to secure the uranium on Desrault for the Sontarans while Gallifrey and the Black Sun were " at each other ' s throats " . ( 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 . Another unnamed species which was eliminated created the reality bomb . ( PROSE : " Sky Pirates ! " ) The Deindum War was fought across time , with Irving Braxiatel and his associates attempting to erase the Deindum from history before they developed into a war - like race . ( PROSE : " Present Danger " ) At one point in the Eighth Doctor ' s future , a war was fought between the Time Lords and the enemy . ( PROSE : " Alien Bodies " ) The Eighth Doctor destroyed Gallifrey while attempting to prevent this war from beginning . ( PROSE : " The Ancestor Cell " ) The Time Lords fought against the Dalek s 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 " ) Tasha Lem warned the Eleventh Doctor that if the Time Lords returned to the universe then the species waiting above Trenzalore — among them the Dalek s , Cybermen , Sontaran s , Terileptil s , Judoon and Weeping Angel s , along with the Slitheen family — would attack them and the Siege of Trenzalore would escalate into another time war . The Daleks managed to break through the Papal Mainframe ' s force field , resulting in a war on Trenzalore and many of the other fleet s were destroyed or retreated overtime . After 900 years of stalemate and with the Doctor dying of old age at the end of his final incarnation , the Time Lords granted him a new cycle of regeneration s , with the resulting regenerative " reset " destroying the Dalek forces , ending the Siege , averting a new Time War , and beginning the Doctor ' s thirteenth incarnation . ( TV : " The Time of the Doctor " )