War Doctor

The "War Doctor" was the post-eighth incarnation of the renegade Time Lord known as the Doctor. (WC: The Night of the Doctor) This Doctor, originally a young and robust incarnation, disowned his namesake when his predecessor realised that a warrior was more appropriate for the unforgiving scope of the Time War. He would spend countless years waging war, ageing significantly more than any other incarnation had ever shown before.

This unknown incarnation of the Doctor was encountered by the Eleventh Doctor and Clara Oswald when they entered the Doctor's own timestream. (TV: The Name of the Doctor)

Biography
After the Eighth Doctor crash landed during the Time War, he was revived temporarily by the Sisterhood of Karn. They offered to control his regeneration so that he could become the person he needed to be to end the Time War. Initially he refused, but after witnessing the death of Cass (the starship's pilot, who refused the Doctor's help because he was a Time Lord) he accepted their help and asked them to make him a warrior. After drinking a potion offered by the Sisterhood, he regenerated into his new incarnation, who promptly rejected the name of the Doctor, declaring, "Doctor no more". (WC: The Night of the Doctor)

This Doctor became known to the Time Lords as "The Renegade", and destroyed Gallifrey and ended the Time War using the Moment. (COMIC: Sky Jacks)

The Eleventh Doctor, upon coming into contact with this incarnation, spurned the very memory of him. He went so far as to suggest this incarnation did not even hold the moniker of "the Doctor" due to his actions in life. He explained to Clara that his real name was not the point; he chose the name "the Doctor" and explained that the name a person chose was like a promise. This unknown incarnation was "the one who broke the promise." He described him as "my secret." This unknown incarnation responded by defending those actions, stating that what he did, he did "without choice" and "in the name of peace and sanity." The Eleventh Doctor acknowledged that as true, but rebutted that it had not been "in the name of the Doctor." As he carried Clara away, the unknown incarnation turned around and watched them with a sombre stare. (TV: The Name of the Doctor)

Behind the scenes

 * Hurt, aged 73 when he first appeared on screen, is the oldest actor to portray the Doctor upon their debut appearance. The second oldest would be William Hartnell, who was 55 years old when the show premiered in 1963.
 * Strax describes this incarnation of the Doctor as having "the look of a battle hardened warrior." (WC: Strax Field Report: The Doctor's Greatest Secret)
 * This incarnation of the Doctor is never named during The Night of The Doctor itself, but is described as the War Doctor in the end credits.

El Doctor (The Name of the Doctor) Доктор (Имя Доктора) הדוקטור (השם של הדוקטור)