He has inherited the wisdom of his original self, the zaniness of his second, the wit of his third, the humour of his fourth incarnation, the occasional use of glasses like his fifth and tenth incarnations, the rashness of his sixth incarnation, the wardrobe sense of his seventh life and the bitterness of his ninth self. The circumstances of his regeneration into this incarnation are ambiguous, much like the transition from his eighth to ninth incarnations. He has had a total of four main companions in his journeys, as well as a fifth for a brief period, who only appears in novelizations
The manner of the Doctor's twelfth regeneration is initially ambiguous, until it is revealed in further detail in the novelization The Trial of the Doctor). The Eleventh Doctor is captured by the High Alliance in the 33rd century, where he is held trial for unknown crimes. Before his fate is decided he is rescued by Anna, but before he can escape in his TARDIS he is shot by an Alliance security officer and his regeneration begins. A dying Doctor farewells Anna in the TARDIS, content that he is not alone. (The Trial of the Doctor/In The Beginning)
Shortly after his regeneration, a weak and still unpredictable Doctor arrived in Dublin, in the year 2013. He had been tracking an alien signal, belonging to a Charth vessel orbiting the earth and preparing for an invasion. Although he had not planned to, the Doctor entered an unknown house and encountered its tenant, Billy O'Hara. With the help of UNIT and Billy he managed to defeat the Charth and survive his regeneration. (In The Beginning).
Adventures with Billy and Isabella
On the first real maiden voyage of the Twelfth Doctor's TARDIS, the Doctor and Billy arrive in New Dublin, a city replacing the former in 2200 after a global war, possibly World War III or IV, the Doctor mentions. There, amidst a futuristic city foreign to both Billy and the Doctor, they encounter an old enemy of the Doctor, the Cult of Skaro. Embittered by his previous encounters with the Daleks, the Doctor spares no mercy for them and destroys the Cult of Skaro. (New Dublin)
The Doctor and Billy explore the carnival like planet of Caltaxi, a planet where the Doctor has been before. He foils the plans of the alien Grand Puppeteer, who is a powerful Degadian archan who destroyed a vessel of Hyperian survivors, rivals of the Degadians. (No Tricks)
On Earth, the Doctor evades the Ice Warriors' plan to freeze the Earth and transform it into a vessel to reclaim Mars, and in the process gains a new companion in Isabella Cartwright. (Mars and Venus/The Frozen Earth)
After joining the crew of the TARDIS, Isabella experiences terror on the gothic world of Gregorae where the Vashta Nerada have devoured the world's inhabitants. The Doctor and his friends manage to escape the dead world. (Count the Shadows)
The Doctor then arrives in 1895 Victorian London, where a sinister cult is trying to raise an inter-dimensional demon. With the aid of Scotland Yard policeman William Eversmythe, the time travelers seal Dagarothon's portal and thwart his plans. (The Doctor and the Demon)
The Doctor was visited by the White Guardian, who warns him that an old evil is returning. The Guardian sends the Doctor and his friends to Medieval Arabia, where a fiery alien is caught between zealous priests and the Holy Wars. The trapped creature is freed, and the Doctor manages to avert a war. (Phoenixfire). The TARDIS subsequently crashes on the distant planet of Manr, where an powerful enemy lies in wait. The Doctor manages to foil the Mara and save Isabella's life. (Serpent's Tongue)
At the request of the White Guardian, the Doctor and his companions are sent to the dead world of Rauchor, where a bloody civil war is ended and the Internal Dark is banished. (The Omens)
Losing A Friend
Arriving on an unnamed planet in the far future, where the United Mining Organization was drilling into the heart of the planet, the Doctor, Billy and Isabella are helpless to stop the resurrection of the first Time Lord, Omega. The Doctor manages to defeat Omega before the world is engulfed into an anti-matter realm, but at the cost of Isabella's life. (Into the Void/The Infinite Realm)
As previously, the Doctor travels with a number of companions, mainly Billy O'Hara, Isabella Cartwright, and Christina. He briefly is joined by an old friend, Captain Jack Harkness also. He values each and everyone one of his companions, and states he would be very lonely without them.
Billy O'Hara is a first of many for the Doctor; he is the first male companion he has had in a long time, and he is the first Irish companion also. The Doctor forms a sort of fatherly and mentor like bond with Billy, who is uninspired and feels as if his life is over.
The Doctor reminds him that Billy is only 23, and the Doctor is 3003. He was born in 1990 and died supposedly in 2064, though this is not known to have changed with the altering of events around that time. Despite his lack of faith in himself and his future, Billy is incredibly resourceful, and the Doctor calls him the TARDIS' technical support. Billy is supportive of Isabella's place on the TARDIS, and they become friends, with Billy looking out for hr in several situations. His family is shown to have still existed in the year 2452, where he meets his distant relative Patrick O'Hara. Billy is brave and honorable, and despite other's showing fear against seemingly impossible threats, he remains brave throughout. By the time Billy parts ways with the Doctor he has earned a lot of faith in himself, and thanks the Doctor for giving him a new goal in life. He is seen in the near future later by the Doctor, at the end of his life, though he tells his old friend that he married and had a full life, recalling to his family that the Earth is being watched by a man in a blue box.
Doctor Isabella Jane Cartwright was born on the 31st of October 1988 in Surrey, and later lived with her grandmother Catherine after 1990, when her parents Jane and Michael were killed in a car accident. She studied medicine in university and came into the employ of Doctor Edward Bradley. She is headstrong, intelligent, though sometimes doubtful and nervous. She is the second companion of the Twelfth Doctor, and considers herself in debt to him after he saved her life her from the Ice Warriors. She becomes friends with him and Billy O'Hara, and although she thinks of herself as independent Billy has to rescue her during their adventures in 19th century London. Due to her role as a doctor, Isabella is apt at medicine and shares her knowledge often.
Though she had a time full of happiness and memories, this was shattered by the Time Lord Omega, who the Doctor and his friends encountered on a distant planet. Omega, annoyed by the Doctor's intervention, tried to kill him with a powerful beam from the Hand of Omega. Isabella, remembering her debt to the Doctor and valuing his life over her own, shielded him, and her body was badly wounded by the Hand. She dies, cradled in the Doctor's arms, and is buried back in London.
Christina is a woman of mystery, she does not tell the Doctor her last name, and she does not tell him a lot of other things. She was supposedly born in London in 1991, making her the youngest of the Twelfth Doctor's companions. She acted as a secretary for various firms before becoming the secretary of local MP Andrew McCoffey, who was really a Slitheen in disguise. He had become enamored by Christina, and decided to remain on Earth in an attempt to swoon her.
Christina is pretty, and often uses this to gain information and influence others. The Doctor however does not fall for her ploys, and is amused by her attempt to outwit him, which he says is impossible. She is initially convinced he is a lot less intelligent than he is, but after she witnesses his skill and power, as well as his dark side, she realizes he is far more complex than she had imagined him to be.
Anna Amelia Andrai
Outside of the show, the Doctor's real "first" companion was Annastasia Amelia Andrai, a woman from the 33rd century who helped his predecessor escape the trial of the High Alliance, though he was fatally shot soon after. The Doctor regenerates and then proceeds to journey with Billy and Isabella before seeing Anna again in Arthemos, which takes place between the first and second episodes of the ninth season. Anna only appears in the literary universe of the Twelfth Doctor, though she is acknowledged in the television series later on.
Anna, properly known as Annastasia Amelia Andrai, was a young Human colonist on the planet Luwei in the 33rd century, and a delegate of the High Alliance, a major alien organization responsible for much of the law in the 33rd century. She met the Doctor when he was being held on trial by the High Alliance for unknown reasons, and promised to set him free, much to his confusion.
In truth Anna had been visited by an unknown woman in her youth telling her that an old friend would be in danger soon, and that he would need Anna's help. Anna had grown up believing that this man would one day appear in her life, and she promised to help him when that time arose.
The next time Anna sees the Doctor is nearly two years later, when he arrives on Luwei in his twelfth incarnation. She is overjoyed to see him, though initially uncomfortable with his new appearance. The Doctor offers her a journey in the TARDIS, which she happily accepts. They journey to the Arthemos in the year 4444, a massive space station wherein humanity and the Chylor are locked in a vicious stalemate that has been going on for almost one hundred and twenty years. The Doctor and Anna help humanity drive back the Chylor.
Lindsay is an eleven year old Aegan/Human From Chall and helps the doctor on many occasions. He helps him in Rennaisance Italy from Weeping Angels, Helps stop a Dalek invasion in Haven(future Earth Sky World), saves humanity by winning the Aegan Gladiators and more.
Lindsay becomes an exorcist, after the weeping angels(his last adventure) and leaves the doctor saying " I'll be gone, but not dead, call me in need of help."
He could be a relitave of a doctor because he reveals"I am human because of my Aunt, my Uncle died after she shot him, near a lake I heard." Also, he can operate the TARDIS very well and can "speak" to it.
The Doctor states his age to be somewhere between 1100 and 1150, though he is uncertain to the exact number. (In The Beginning).
Though the Doctor is youthful in his appearance, he is probably the most grounded and savvy of his incarnations. He is wry and sporadic, like his fourth incarnation, and values his TARDIS and sonic screwdriver highly, saying he'd just be a marooned alien, as he was during his third life. Although he has had many years of experience with the human race he is still sometimes alien to them in his behaviors and personality.
Despite his easy going personality, he is shown to be incredibly aggressive and bitter when he is dealing with older enemies, notably the Daleks and Omega. This bitterness and loathing is countered by his sympathy, seen most notably with the Wooden Cyberman in the Heart of Wood, a being he feels is harmless to the human race, without the void of a soul the Cybermen possess.
Habits and Quirks
Like his fifth and tenth incarnations, the Doctor is known to wear glasses, though a lot less frequently than his counterparts. He is also seen carrying a cane, a cross, and a myriad of other bizarre items found in the halls of the TARDIS. He is also highly unpredictable, and will often trail off into babble that his companions would not understand. He is particularly fond of history, and expresses a knowledge of much of the Earth's, most likely due to his many adventures through the timeline of mankind.
The Twelfth Doctor is not a stark contrast from his previous self, though he does appear a few years younger and obviously physically different. He has black hair, similar in length as before, and blue eyes. During and briefly after his regeneration he wears the same outfit as his predecessor, before changing his wardrobe. He wears long black trousers and black shoes, a shirt covered in question marks, a blue jacket and collar, and a tie. He regards this as his formal attire, and is adamant he will choose a more personal wardrobe.
On several occassions he dons clothing suitable of the place or era, eg. in 19th century London he sports a much more old fashioned jacket, in 12th century Arabia he wears a simpler outfit with a cross around his neck, to "mediate". He often does not wear his jacket when off board the TARDIS, as it is cumbersome. The Twelfth Doctor's TARDIS, often referred to as TARDIS MARK XII, is largely unchanged on the outside, though the inside is an amalgam of his previous TARDIS, and that of his fourth and seventh incarnations.