Time war
The Time War was a conflict between the Time Lords and the Daleks. Several other species, such as the Nestene Conciousness and the Gelth, were also involved, though whether they were actual participants or merely had the misfortune of being caught in the crossfire is uncertain. What is known is that the Time Lords and their homeworld of Gallifrey were destroyed, leaving the Doctor as the only known survivor. The entire Dalek fleet, save the Emperor's ship and one lone Dalek soldier, were also destroyed. The Time War finally ended in the year 200,100, when the entity known as "Bad Wolf" destroyed the Dalek Emperor and the new army of Daleks he had been building.