The Warrior's universe

In one parallel universe, the Fourth Doctor chose to destroy the Daleks at their creation.

History
During his mission to interfere with the creation of the Daleks (TV: Genesis of the Daleks), Sarah Jane Smith successfully convinced the Fourth Doctor to destroy the Daleks. However, since the Time Lords who sent the Doctor on his mission had been from a point in time when they were engaged with the Daleks in the Last Great Time War, this had massive repercussions, drawing the universe into the Time War much sooner than before, and with the Daleks still existing, despite the Doctor's efforts. As for the Doctor and his companions, they tried to escape Skaro via the Time Ring, but were shot by a prototype Dalek. Before the Doctor could die, he was extracted from Skaro by Narvin, who provided the Doctor with the Elixir of Life, triggering his regeneration into the Warrior. (AUDIO: Dust Devil)