List of causes of regeneration

The causes of regeneration, especially amongst Time Lords, were many and varied.

The following are the known causes of regeneration of specific Time Lords.

The Doctor

 * First Doctor: Life force syphoned from him by the planet Mondas, forcing a regeneration from exhaustion and a loss of strength. (DW: The Tenth Planet)
 * Second Doctor: Forced to regenerate by the Time Lords as part of his sentence. (DW: The War Games)
 * Third Doctor: Radiation poisoning upon prolonged exposure to the Great One's highly unstable web of Metebelis crystals and had his regeneration triggered by K'anpo Rimpoche to compensate for the Doctor's body being unable to trigger it himself. (DW: Planet of Spiders)
 * Fourth Doctor: Fell to the ground from a great height after battling the Master at the Pharos Project; merged with the Watcher to trigger regeneration. (DW: Logopolis)
 * Fifth Doctor: Contracted spectrox toxaemia on Androzani Minor, triggering regeneration. (DW: The Caves of Androzani)
 * Sixth Doctor: TBA. (DW: The Horrors of War)
 * Seventh Doctor: Poisoned by Henrick by Iron put in his Earl Grey tea at Margrave University while under the influence of the Metatraxi. (DW: Blood and Iron)
 * Eighth Doctor: TBA. (DW: Hatred of the Daleks)
 * Ninth Doctor: In order to save the lives of his companion, Sammy Thompson, and scullery maid, Edith, as well as several other civilians under the control of Edward Grove, the Doctor stabbed himself through the hearts, ending a paradox and sacrificing his life. (DW: The Chimes of Midnight)
 * Tenth Doctor: Killed when The Keeper forced him to use the Sulphric Device to fully repair the time distortions. (MOV: Doctor Who)
 * Eleventh Doctor: Killed in a mind-bending contest against the Master which would have terminated all of his remaining lives however Ohila of the Sisterhood of Karn triggers his regeneration with a potion devised from the Elixir of Life. (MOV: Doctor Who: Revelation)
 * Twelfth Doctor: Fell through the Time Vortex and suffocates through the vacuum before falling into the TARDIS. (MOV: Doctor Who: Vengeance)
 * Thirteenth Doctor: Sacrificed himself to close the Eye of Harmony and protect the universe against the Valeyard. (MOV: Doctor Who: Endgame)
 * The Thirteenth Doctor died after this event, and didn't regenerate. He only later regenerated when the bodies of Will Adams and Phaedra were merged together to form Connie, by the Rogue, which when coupled with the Thirteenth Doctor's matrix consciousness, triggered regeneration into his Fourteenth self. (PAN: Survivors, Doctor, MOV: Doctor Who: Genesis)


 * Fourteenth Doctor: Ambushed by a Cyberman and subsequently converted into one, triggering the regenerative process. (DW: The Third Planet)
 * Fifteenth Doctor: Sacrificed herself to save trillions of lives from dangerous ore reacting with an ion storm. (DW: Her Final Stand)