Twelfth General

Kenossium, commonly referred to as simply the General, was a General in the Time Lord military.

Early days
Kenossium was, for her first ten incarnations, a woman. (TV: Hell Bent) Like all Time Lords, she was taken from her family at the age of eight for the selection process in the Drylands. Staring into the Untempered Schism as part of a Time Lord initiation rite, she was inspired by what she saw in the Schism. (PROSE: A Brief History of Time Lords)

At the Time Lord Academy, Kenossium was mentored by Bellator, whose lessons taught her how to survive "sixteen transwarp campaigns and a Time War." (COMIC: The Clockwise War) She became the Time Lords' military commander, (TV: Hell Bent) with the rank and title of "the General". (TV: The Day of the Doctor)

The General was present on Gallifrey when the First Doctor stole a TARDIS, and also witnessed the commotion caused by the event. (PROSE: The Day of the Doctor)

The General's incarnations
The General's tenth regeneration resulted in a male eleventh incarnation. He appeared as a grey-eyed middle-aged light-skinned bald man (TV: The Day of the Doctor, PROSE: Lords and Masters).

After the Twelfth Doctor shot him, the General regenerated into their twelfth body, this time having the form of a dark-skinned woman with a shaven head. (TV: Hell Bent)

Later life
Many years after the conclusion of the Time War, the General would deny that additional Doctors other than the war, tenth and eleventh incarnations were present in the saving of Gallifrey. (PROSE: A Brief History of Time Lords)

Eleventh incarnation
During the Last Great Time War, the General was devoted to defeating the Daleks and saving his species. He was shown to be a greatly respected military leader who didn't seem impressed with Rassilon and the High Council's plans to save their species. He was also shown to not think highly of the War Doctor, calling him "the mad fool" and saying that three Doctors arriving was "all [his] worst nightmares at once" and that twelve of them turning up was even worse. He was also stunned by the idea that Gallifrey and the Time Lords' only option was to be frozen in a pocket universe and was knowledgeable about the fact that it would take a very long time to make such calculations. However, he was shown to be able to make quick decisions when the need arose, such as when the Dalek Fleet increased their firepower on Gallifrey and he ordered the Doctor to "just do it" rather than continuing to hesitate over his decision. (TV: The Day of the Doctor)

Following the end of the Last Great Time War, the General gained a great respect for the Twelfth Doctor. When Rassilon questioned who the Doctor thought he was ignoring the military, the General called him "the man who won the Time War" with a respectful tone. When Rassilon ordered the Doctor's execution, the General protested but chose not to disobey orders like his men. However, he also did nothing to stop his men as they sided with the Doctor. When the General defected to the Doctor's side, he ordered Rassilon off Gallifrey in a way that showed he was disgusted with the former Lord President. He did, however, question the Doctor's decision to banish Rassilon, as there could be nowhere for him to go and Rassilon was once a good man. He accepted the decision regardless though.

When he realised the Doctor had manipulated the situation to save Clara Oswald, the General showed no fear as he stood his ground against an armed Doctor, merely trying to get him to stand down. When the Doctor wished him good luck before shooting him, the General did the same, remaining magnanimous towards him to the end despite the fact that the Doctor was about to shoot him. (TV: Hell Bent)

Twelfth incarnation
As a woman, the General showed a distaste for the egos of men and was at least partly relieved to be a woman again. While trying to stop the Doctor, she allowed Clara to say some final words to him before she was sent back to die, showing some compassion and listened stoically as Clara called the Time Lords monsters. However, she was shocked by the Doctor's escape with Clara's help and somewhat panicked by it. (TV: Hell Bent)

She showed great respect for Bellator, due to him being an old mentor of hers. Originally being cheerful, she turned to vicious anger after Bellator died. Although continuing to respect the Doctor by willingly helping him when necessary, she was not afraid to turn against his wishes when the fate of Gallifrey was on the line. (COMIC: The Clockwise War)

Behind the scenes

 * In their first-seen incarnation, the General was played by Ken Bones, who also provided the Time Lord voice asking the Question, "Doctor who?", in The Time of the Doctor. A connection between the voice heard in The Time of the Doctor and the General was never made explicit, although the subtitles on the Blu-Ray and DVD identify the voice as that of "the General".
 * The General's regeneration in Hell Bent marked the first time a gender-swapped regeneration was shown on television. Michelle Gomez's was the first gender-swapped Time Lord depicted on television, but her actual regeneration occurred off-screen. The very first gender-swapped regeneration was depicted in AUDIO: The Black Hole, which was released two weeks before Hell Bent.
 * Incidentally, it was also the first regeneration witnessed in the revived series where the Time Lord in question was lying down, rather than standing up, and the regeneration was far calmer than is generally seen with Time Lords such as the Doctor and.
 * The General's birth name Kenossium, as revealed in COMIC: The Clockwise War, is a combination of the name Ken and the Latin word "ossium" meaning "bones". It is, therefore, a subtle reference to the actor Ken Bones, who played the eleventh incarnation.
 * According to TARDIS Type 40 Instruction Manual, Kenossium wrote an unofficial memoir titled "Thirteen of Them: I Didn't Know When I Was Well Off", which detailed the events at the climax of the Last Great Time War.
 * Following the revelation in Hell Bent that all of the General's regenerations prior to the Ken Bones incarnation had been female, a fan theory emerged that "the General" was a new identity adopted by Romana at the end of the Last Great Time War. Although contradicted by a handful of sources (most notably The Clockwise War giving the General a different birth name from " Romanadvoratrelundar", and the Twelfth Doctor Doctor Who Experience Interactive Story depicting Romana still in her Lalla Ward incarnation in "the very last days of Gallifrey"), this idea was endorsed by veteran Doctor Who writer Jonathan Morris, who indicated in 2020 that he intended to confirm it in a licensed short story at the first opportunity.