Now that the Twelfth Doctor has met his end, let’s look at every single regeneration in the history of Doctor Who…
The First Doctor
Story: The Tenth Planet (1966)
Cause of Regeneration: Simple old age. After the Cybermen’s first invasion of Earth, the elderly First Doctor collapsed, complaining that his body was “wearing thin.”
Last Words: “It’s far from being all over.”*
*’Twice Upon a Time’ reveals it is actually “Here we go.”
The Second Doctor
Story: The War Games (1969)
Cause of Regeneration: Execution. Captured by his people, the Time Lords, the Doctor was forcibly regenerated and exiled to Earth for breaking their cardinal rule of interfering with time.
Last Words: “No, stop! You’re making my giddy…”
The Third Doctor
Story: Planet of the Spiders (1974)
Cause of Regeneration: Radiation Poisoning. While stopping the evil alien spiders of Metebelis 3, the Third Doctor was exposed to deadly radiation. This is the first time the process was called “regeneration.”
Last Words: “A tear, Sarah Jane? No. Where there’s life, there’s a…”
The Fourth Doctor
Story: Logopolis (1981)
Cause of Regeneration: Fall from a great height. The Fourth Doctor fell off a radio telescope while stopping the Master from seizing control of the universe. Uniquely, this regeneration included a ghostly intermediate stage.
Last Words: “It’s the end… But the moment has been prepared for.”
The Fifth Doctor
Story: The Caves of Androzani (1984)
Cause of Regeneration: Toxic poisoning. With only one cure for fatal Spectrox poisoning left, the Doctor gave it to his friend, Peri. This regeneration caused the Doctor to hallucinate his past friends and enemies.
Last Words: “… Feels different this time.”