The General
The General was the Time Lord military commander during the Time War and then after.
Biography
As her twelfth incarnation stated, the first ten of the General's incarnations were female. When she underwent her tenth regeneration, she became a male for the first time. (TV: Hell Bent)
Eleventh incarnation
The General's eleventh incarnation appeared as a middle-aged light skinned male with no hair. He described himself as the Time Lords' military commander. (TV: Hell Bent)
The General led the War Council and its efforts to defend Gallifrey from the Dalek onslaught in the final days of the Last Great Time War. In the aftermath of the Fall of Arcadia, he was informed of the War Doctor's appearance there. He was then alerted to a security breach in the Time Vaults, discovering the Doctor had taken the Moment, and intended to use it.
He was later contacted by three incarnations of the Doctor, much to his displeasure, the War Doctor with the Tenth and Eleventh Doctor, who revealed to him their plan to save Gallifrey by freezing it before its destruction and shifting it to a pocket universe. The General was sceptical, shocked by the thought of being lost and forgotten in another universe and that the calculations would take centuries. The Doctors informed him that they have recruited all their incarnations to help and that while the Time Lords would be lost, they'd at least have hope which they didn't have at that point. The Doctors also told the General that the alternative was burning and no one wanted that. As the General continued to hesitate, the Dalek fleet realised something was wrong and increased their firepower. Realising he was out of options, the General ordered the Doctor to "just do it." The thirteen Doctors then succeeded in freezing Gallifrey and shifting it a pocket universe, causing the Dalek fleet to destroy themselves while the Time Lords were saved. (TV: The Day of the Doctor)
When the Twelfth Doctor returned to Gallifrey, the General discussed the event with Rassilon and the High Council. He told Rassilon that the Doctor had the respect of his men as he was the one who won the Time War and had served with many of them. When Rassilon ordered the firing squad to kill the Doctor, the General protested, but made no move to stop them. The squad purposefully missed and sided with the Doctor. When military ships arrived, Rassilon assumed the General had summoned them. However, the Doctor told Rassilon he'd called the ships not the General and the ships chose to provide the Doctor with backup. As Rassilon prepared to kill the Doctor was his gauntlet, the General stopped him, telling Rassilon "Lord President, with respect, get off his planet." The General then dropped his gun and stood at the Doctor's side against Rassilon. Rassilon was exiled from Gallifrey and the General informed the Doctor that Gallifrey was at "the end of the universe, give or take a star system" and as such, Rassilon may have nowhere to go. When the General continued to call Rassilon the President, the Doctor corrected him that he was the President now. The Doctor agreed to assist the High Council in learning the true identity of the Hybrid. To do this, he claimed that Clara Oswald had vital information and insisted she be extracted from the point of her death and brought to him on Gallifrey. The General facilitated this, but quickly discovered that the Doctor had merely lied in an extraordinary attempt to save Clara.
The General insisted that any attempt to prevent Clara’s death as an established historical event would have grave consequences for the timeline. Unperturbed, the Doctor shot the General after asking the incarnation he was in, causing his eleventh regeneration. (TV: Hell Bent)
Twelfth incarnation
The General quickly recovered after regenerating, returning to the form of a woman, in this case a dark skinned woman with a shaven head. She observed that she was "back to normal" and rhetorically asked how men continually dealt with "all that ego". With assistance from Ohila, the General continued to pursue the Doctor into the Cloisters. She exchanged words with Clara and seemed to respect the human's opinion. Unfortunately for the General, Clara had been buying enough time for the Doctor to escape and steal another TARDIS, and the pair fled from Gallifrey. (TV: Hell Bent)
Personality
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 Doctor, calling him "the mad fool" and saying that three Doctors arriving was "all my 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 is shown to be able to make quick decisions when the need arises as seen 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 his war incarnation "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 may 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 talk some sense into him and get him to stand down. When the Doctor asked which regeneration the General was in, the General seemed to understand what he meant but again showed no fear. 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, possibly being understanding what the Doctor was trying to do despite the extreme measures he was using. (TV: Hell Bent)
Twelfth incarnation
As a woman, the General showed 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)
Behind the scenes
In his 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. Although not explicitly confirmed, it can be inferred that the voice asking the Question was that of the General. Indeed, the subtitles on the Blu-Ray and DVD identify the voice as that of the General.
The General's eleventh regeneration in Hell Bent marked the first time a gender-swapped regeneration was shown on television. Michelle Gomez's Missy 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.