10 Major Doctor Who Events That Changed Everything

2. Saving Gallifrey

So within the space of this list alone, we've met the Time Lords. We've seen the moment they accidentally caused the war that would see them all reduced to a cosmic cinder. How else could they possibly serve to change everything we knew about the show? By being saved from the brink of destruction by every single incarnation of The Doctor that had ever existed at that point, and then one. That's how!

The fiftieth anniversary special 'The Day of the Doctor' revisited The Doctor's post-war grief over the death of their species and forced them to face the consequences of their actions through meeting The War Doctor. However, showrunner and writer Steven Moffat decided to pull a characteristically clever cat out of his bag and provided fans with a scenario we never thought we would see in the revival of the show, after previous series had already made it so fundamentally clear that The Doctor was now the last of their kind: What if The Doctor could save Gallifrey?

At the very last minute, Gallifrey is frozen within an instance of time, lost to the universe but still very much alive. No longer is The Doctor alone in the universe. And the ways that this decision helped to ensure a fresh future for Doctor Who had only just begun. Even though The Doctor seems to forget about their quest to find Gallifrey almost immediately after starting their quest in Series 8, it's their decision to save Gallifrey that allows the Time Lords to grant a new regeneration cycle to the dying Eleventh Doctor in 'Time of the Doctor'. From that point on, The Doctor has been living a new lifecycle, a feat that only The Master has ever been seen to do before in the show's history, and even they didn't do wonders at keeping in good shape with that.

For quite literally allowing Doctor Who to keep going forth into the universe after coming so close to snuffing it once and for all, the Resurrection of Gallifrey and the Time Lords has to be on this list.