Aliases of the Doctor Throughout their travels in time and space , the Doctor took on and was called by a number of different aliases , titles and names . Some were fleeting . Others , like John Smith , were used by almost all of their incarnations . The Doctor ’ s incarnations told few individuals their real name . Instead , they asked others to call them simply , the Doctor . The Doctor ' s real name . As the Time Lord ' s true name was not generally known , " the Doctor " ( or " Doctor Who " ) became an alias . It was implied that his given name was ceremoniously withdrawn and stricken by his Cousins as punishment for a disgrace he brought upon his House . ( PROSE : " Lungbarrow " ) Even when put on trial by the Time Lord s , he was only referred to as " the Doctor " , ( TV : " The War Games " ) although the Valeyard , a culmination of the Doctor ' s darker side who prosecuted the second trial , acknowledged that this was an alias . ( TV : " The Mysterious Planet " ) Even those who had known him in childhood addressed him only as " the Doctor " , such as the Master , ( TV : " Death in Heaven " ) and the Rani . ( COMIC : " Weapons of Past Destruction " ) When the Fifth Doctor was officially inducted as Lord President , he declared that it was " out of the question " for him to be introduced by his true name , stating that he would accept being introduced as ' Lord President Doctor ' ( AUDIO : " Time in Office " ) . According to one account , during their first incarnation , the Doctor adopted this name in dealing with human colonists on the planet Iwa at the same time that his granddaughter adopted the name " Susan " . ( PROSE : " Frayed " ) Another account implied that the Doctor ' s title had been chosen as a Gallifreyan custom , ( TV : " The Sound of Drums " ) and that he had been using it before he left Gallifrey . ( TV : " The Name of the Doctor " ) The Doctor ' s real name has been said to be difficult to pronounce , for human s at least , ( AUDIO : " Slipback " ) and certainly for adults , ( TV : " Twice Upon a Time " ) possessing thirty eight syllables . ( PROSE : " Sleepy " ) The First Doctor once told an interrogator he " wouldn ' t be able to pronounce the first syllable of [ his name ] . " ( PROSE : " Salvation " ) His seventh incarnation likewise told one of his captors that he " doubt [ ed ] [ they ] ' d be able to pronounce the name [ he ] was originally given . " ( PROSE : " Illegal Alien " ) When asked about the Doctor ' s name , Peri Brown once said that the Doctor had told her she would find it unpronounceable . ( AUDIO : " Slipback " ) The Doctor kept their true name hidden despite numerous " mind - probe " attempts and the effect of a truth field . ( TV : " The Girl in the Fireplace " , " The Time of the Doctor " ) The Carrionite Lilith , unable to discover the Tenth Doctor ' s true name even with the " witchcraft " used by her kind , remarked , " There is no name , " and that the Doctor was hiding his true name in despair . ( TV : " The Shakespeare Code " ) The psychically - gifted Evelina , who attempted to foretell the Doctor ' s future , remarked that his " true name " was " hidden " from her . ( TV : " The Fires of Pompeii " ) Moments before regenerating into the Thirteenth Doctor , the Twelfth Doctor told his future self that they " mustn ' t tell anyone your name " , before noting " they wouldn ' t understand it anyway . " He acknowledged , however , that " children can hear it , sometimes . If their hearts are in the right place , and the stars are too . Children can hear your name . But nobody else , nobody else ever . " ( TV : " Twice Upon a Time " ) Significance . The Eleventh Doctor told Clara Oswald that his real name was not important , since he specifically chose the title of " Doctor " to take its place , saying it was " like a promise you make . " ( TV : " The Name of the Doctor " ) This promise was , as recited by the Tenth and War Doctor s ; " Never cruel or cowardly . Never give up , never give in . " ( TV : " The Day of the Doctor " ) Despite their hatred of the War Doctor ' s actions , ( TV : " The Name of the Doctor " ) both the Tenth and Eleventh Doctors admitted " [ he ] was the Doctor more than [ any of them ] . " ( TV : " The Day of the Doctor " ) When Clara was forced to take on his role for him , the Twelfth Doctor told her that " goodness has nothing to do with [ being a Doctor ] " . ( TV : " Flatline " ) The Doctor considered abandoning his name if he felt he had to do something highly immoral ( TV : " The Beast Below " , " Face the Raven " ) The Doctor went by the title of Warrior during the Time War , but proudly called himself the Doctor once he discovered the true outcome of the War . ( TV : " The Day of the Doctor " ) According to Dorium Maldovar , the Silence had a particular interest in the Doctor ' s name . He explained that if the Doctor lived long enough , " on the fields of Trenzalore , at the fall of the Eleventh , [ when ] no creature could speak falsely or fail to answer " , a question that must never be answered would be asked : " Doctor Who ? " . The Silence wanted to stop the Doctor from revealing his true name . ( TV : " The Wedding of River Song " ) The Doctor was at a later time forced to go to Trenzalore to rescue his friends from the Great Intelligence , which sought to gain access to the Doctor ' s tomb . The tomb , which was a future version of his own dying TARDIS , would open only to the Doctor ' s real name . The Intelligence threatened to kill Clara Oswald and the Paternoster Gang if he did not speak his name and open the tomb ; the situation was resolved when the data ghost of River Song was able to silently transmit his name to the TARDIS , thus opening the door for the Great Intelligence . ( TV : " The Name of the Doctor " ) The Doctor ' s real name became important during the Siege of Trenzalore , as it was the signal chosen by the Time Lords to come back to the universe , broadcasting the question ' Doctor Who ? ' through a crack in reality , simultaneously broadcasting a Truth Field so that they could be sure that it was truly the Doctor responding to them . Despite this , when the Doctor was facing death , Clara told the Time Lords through the Crack that the only name of his that mattered was " the Doctor " and everything he stood for under that name , prompting them to give the Doctor a new regeneration cycle at the cost of closing the crack . ( TV : " The Time of the Doctor " ) After meeting his twelfth incarnation , the First Doctor was confronted by the mysterious Testimony Foundation , who claimed that the Doctor was the " Doctor of War " . Although the First Doctor initially feared this interpretation of his future , after witnessing his future self ' s efforts to save Captain Archibald Hamish Lethbridge - Stewart , he came to conclude that the " Doctor of War " was not a man who reveled in war , but a man who sought the moments of peace that existed amid open warfare , and who would always try to find another way to end war , and to find resolution , rather than resorting to bloodshed . ( TV : " Twice Upon a Time " ) Ubiquity of the title . The Doctor did possess at least one doctorate . ( TV : " The Moonbase " , " The Armageddon Factor " , " The Mysterious Planet " ) They sometimes described themselves as a " doctor of many things " ( TV : " Four to Doomsday " ) or of " everything " . ( TV : " Spearhead from Space " , " Utopia " ) However , their knowledge was limited to anything prior to the Rassilon Era . ( TV : " Utopia " ) The Eleventh Doctor claimed that one of his doctorates was in cheesemaking , ( TV : " The God Complex " ) but only the " stinky , blue kind " . ( PROSE : " Shroud of Sorrow " ) On several occasions , the Doctor stated they were not a medical doctor , ( TV : " The Forest of Fear " , " Mighty Kublai Khan " ) though did note that , by their second incarnation , he had studied medicine in the 19th century , ( TV : " The Moonbase " ) although the Twelfth Doctor claimed to have graduated in the wrong century . ( TV : " Death in Heaven " ) Individuals with knowledge of his name . Susan Foreman knew the Doctor ' s real name , and wrote it on the wrappings of a hypercube she sent to him after she had settled down on Earth . ( PROSE : " Ghost of Christmas Past " ) The Sixth Doctor told his dance instructor , Becky , his name . ( PROSE : " Teach Yourself Ballroom Dancing " ) The Eighth Doctor ' s companion , Samantha Jones , overheard his real name being said . She found it quite alien and virtually unpronounceable . ( PROSE : " Vanderdeken ' s Children " ) When the Tenth Doctor first encountered her , River Song claimed to have known him at some point in his future , ( TV : " Silence in the Library " ) and , to prove her " credentials " , she whispered his name in his ear , and apologised for having to do so . The Doctor was shocked at this , as " there [ was ] only one reason [ he ] would ever tell anyone [ his ] name , [ and ] only one time [ he ] could . " ( TV : " Forest of the Dead " ) River indicated to Clara Oswald that she " made " the Doctor tell her his name and that " it took a lot of effort " . ( TV : " The Name of the Doctor " ) Near the end of his tenth incarnation , despite believing there was no one left in the universe who knew it , the Doctor encountered members of an unidentified pan - dimensional race that knew his real name . ( AUDIO : " The Last Voyage " ) While separated from the Eleventh Doctor , Clara Oswald read his name in " The History of the Time War " . That timeline was later averted , however , leaving her with no memory of it , ( TV : " Journey to the Centre of the TARDIS " ) though she later began to recall certain moments of the timeline , ( TV : " The Name of the Doctor " ) and claimed to know the Doctor ' s name when bluffing to the Cybermen about being the Doctor . ( TV : " Death in Heaven " ) Commonly used aliases . John Smith . John Smith was an alias the Doctor frequently used on Earth and around human s when a " standard " name was needed . It was often preceded by the title " Doctor " , though not always — for example , when he was undercover as a teacher at a school or a patient in a hospital . ( TV : " School Reunion " , " Smith and Jones " ) As " John Smith " was considered a generic name in some Earth cultures , the Doctor ' s use of the alias was occasionally treated with scepticism . ( TV : " Midnight " ) During their first incarnation , the Doctor used a library card with the name Dr J . Smith while living at 76 Totter ' s Lane , ( TV : " The Vampires of Venice " ) as well as for identification when renting the junkyard . ( PROSE : " The Rag & Bone Man ' s Story " ) The inspiration for the alias was John Smith of John Smith and the Common Men , with which he was familiar through Susan . ( PROSE : " The Witch Hunters " ) In their second incarnation , the name was independently used by his companion Jamie McCrimmon while the Doctor was being treated for concussion , as he saw it being used as a brand name on a metal container . ( TV : " The Wheel in Space " ) Likewise , Chang Lee chose to register the name for the Seventh Doctor while he was en route to get his bullet wounds healed . ( TV : " Doctor Who " ) The Doctor adopted it on a semi - regular basis during their third incarnation while exiled on Earth , when he served as unpaid scientific advisor to UNIT . ( TV : " Spearhead from Space " , " Inferno " , " The Time Warrior " ) The Doctor twice changed himself into a human who used the name John Smith . This occurred in their seventh incarnation , ( PROSE : " Human Nature " ) and in their tenth incarnation . ( TV : " Human Nature " ) Often , the Doctor would use variations of the name , like the online handle " jsmith " , jsmith8 " , ( PROSE : " Blue Box " , " Lonely " ) the French variation " Jean Forgeron " , ( COMIC : " The Forgotten " ) or the German translation " Johann Schmidt " . ( PROSE : " The Shadow in the Glass " , AUDIO : " Storm Warning " , et al . ) Doctor Who . The name " Doctor Who " was applied to the Doctor on several occasions . When the First Doctor was using the name " Doctor Caligari " and someone remarked " Doctor who ? " he replied " Yes , quite right . " ( TV : " The Gunfighters " ) The computer WOTAN repeatedly referred to the First Doctor as " Doctor Who " . ( TV : " The War Machines " ) Both Ian Chesterton and Vicki occasionally called the Doctor " Doctor Who " . ( PROSE : " Doctor Who and the Zarbi " ) The Second Doctor briefly used the name Doktor von Wer ( literally , " Doctor [ of ] Who " ) during his visit to Scotland on 16 April 1746 ( TV : " The Highlanders " ) and once signed a message as " Dr W . " ( TV : " The Underwater Menace " ) The Zaon s called him Doctor Who . ( PROSE : " Daleks Invade Zaos " ) Bessie ' s license plate during the Third Doctor ' s time at UNIT read " WHO 1 " ; ( TV : " Doctor Who and the Silurians " ) in the Doctor ' s seventh incarnation it read " WHO 7 " , ( TV : " Battlefield " ) and " WHO 8 " in his eighth incarnation . ( PROSE : " The Dying Days " ) Miss Hawthorne referred to the Third Doctor as " the great wizard Qui Quae Quod " ; those three words all mean " who " in Latin . ( TV : " The Dæmons " ) The Fourth Doctor wrote a series of children ' s books during his time with UNIT which were mistakenly published under the name " Doctor Who " : they were intended to be " The Doctor , Who Discovers Historical Mysteries " , but the publishers presented it as " Doctor Who Discovers Historical Mysteries " . ( AUDIO : " The Kingmaker " ) The Curator tapped his own nose when saying , " Who knows . " ( TV : " The Day of the Doctor " ) K9 was heard on occasion making playful remarks related to the Who name . ( TV : " A Girl ' s Best Friend " , " Invasion of the Bane " ) Clive Finch ' s website called him " Doctor Who " . ( TV : " Rose " ) Upon reading the Tenth Doctor ' s mind , Reinette remarked that " Doctor Who " was " more than just a secret " . ( TV : " The Girl in the Fireplace " ) The oldest question in the universe was " Doctor Who ? " ( TV : " The Wedding of River Song " ) The version of the Doctor in the Land of Fiction was known as Dr . Who . ( PROSE : " Prelude Conundrum " , " Conundrum " , " Head Games " ) Theta Sigma . Theta Sigma , informally Thete and occasionally spelt " ΘΣ " , was a nickname of the Doctor at the Time Lord Academy on Gallifrey . ( TV : " The Armageddon Factor " , " The Happiness Patrol " ; COMIC : " Flashback " ) It identified him uniquely amongst the Time Lords and was not to be spoken outside of the Academy . ( PROSE : " Falls the Shadow " ) When the Doctor ' s final incarnation permanently died during the first battle of the War , his coffin had the symbols for " Theta " and " Sigma " on it . ( PROSE : " Alien Bodies " ) In an alternative timeline in which Rassilon failed to finish the Eye of Harmony before his death , the Doctor never left Gallifrey and became a commentator rather than a renegade Time Lord . He was known as Commentator Theta Sigma . ( AUDIO : " Forever " ) Theta Sigma was part of River Song ' s message to the Doctor on the universe ' s oldest cliff - face . ( TV : " The Pandorica Opens " ) K9 was improved by Time Lord Theta Sigma . ( PROSE : " K9 and the Beasts of Vega " ) Oncoming Storm . The Doctor was referred to as the " Oncoming Storm " by the Draconian s , ( PROSE : " Love and War " ) and in " the ancient legends of the Dalek homeworld " . ( TV : " The Parting of the Ways " ) In Draconian , the title was pronounced " Karshtakavaar " . ( PROSE : " Love and War " ) After being told of the title by the Ninth Doctor , ( TV : " The Parting of the Ways " ) Rose Tyler called the Tenth Doctor by the " Oncoming Storm " when she and Mickey Smith were being prepared for dissection by the Clockwork Droid s . ( TV : " The Girl in the Fireplace " ) The Tenth Doctor later introduced himself as the " Oncoming Storm " to a Dalek aboard of the " Wayfarer " , ( PROSE : " Prisoner of the Daleks " ) and referred to the title when confronting a rabbit he thought was a Zygon . ( TV : " The Day of the Doctor " ) The Eleventh Doctor began calling himself the " Oncoming Storm " when he misinterpreted Sean ' s request to help the " King ' s Arms " football team " annihilate " another team at a match . ( TV : " The Lodger " ) He later referred to the title when the Daleks forgot him . ( TV : " Asylum of the Daleks " ) As early as their second incarnation , the Doctor knew that the Daleks had also given them the epithet " Ka Faraq Gatri " , ( COMIC : " Bringer of Darkness " ) which translated as " Destroyer of Worlds " . ( PROSE : " " ) or possibly " Nice guy , if you ' re a biped " . ( PROSE : " Continuity Errors " ) He had been awarded the name upon orchestrating the destruction of the Dalek home planet Skaro in his seventh incarnation , ( TV : " Remembrance of the Daleks " ) though the Daleks also used it prior to Skaro ' s destruction . ( COMIC : " Bringer of Darkness " ) Davros also referred to the Doctor as " the Destroyer of Worlds " after the Meta - Crisis Tenth Doctor destroyed the New Dalek Empire on the Crucible . ( TV : " Journey ' s End " ) Other aliases . The following is a list of aliases used by the Doctor in each of their incarnations . Nicknames . A list of names other individuals have called the Doctor throughout his travels .