PHOTOS - One Year On: The Day Of The Doctor Aired A Year Ago Today

This time last year Doctor Who fans around the world were celebrating an amazing milestone for the show: its 50th birthday. The very first episode of the iconic series went out on BBC TV on November 23rd 1963. The first part of a four-episode adventure, An Unearthly Child, starred William Hartnell as the crotchety and enigmatic alien who would go on to find himself fans across the globe and still be watched well into the 21st Century.

Central to the BBC's 50th Anniversary celebrations was a specially filmed adventure The Day Of The Doctor. In keeping with the tradition of bringing back old incarnations of the Time Lord, Matt Smith, the Eleventh Doctor was joined by his predecessor David Tennant to face classic foes the Daleks and the Zygons. In addition, the special introduced a third, previously unknown incarnation, the War Doctor, played by John Hurt, whose origin as a regeneration of the Eighth Doctor (Paul McGann) was explained in the online minisode The Night Of The Doctor. The cast also saw the return of Billie Piper as Rose Tyler, alongside Jenna Coleman, Jemma Redgrave and Joanna Page. All of the previous incarnations of the Doctor were glimpsed in the explosive finale, with a surprise sneak peek at Matt's successor, Peter Capaldi. To the delight of fans, the special also featured a cameo appearance by Tom Baker.

The episode revolves around the last day of the Time War, the day in which the Doctor chose to destroy both the Daleks and his own people in order to end the conflict and save the rest of the Universe using a stolen sentient weapon called The Moment. 

In the present day, the Eleventh Doctor (Matt Smith) and Clara (Jenna Coleman) are brought to the National Gallery by Kate Stewart (Jemma Redgrave) of UNIT to examine some paintings from which something has broken out from the inside. And in 1562, the Tenth Doctor (David Tennant) is busy wooing Queen Elizabeth I (Joanna Page) in order to expose her as a Zygon in hiding. A fissure in time opens up which allows the two Doctors to meet. They are soon joined by the War Doctor (John Hurt) who has been granted a vision of his future selves by The Moment which has taken on the physical form of Rose Tyler (Billie Piper).

In the present day, Zygons have emerged from stasis cubes hidden in paintings and have taken control of UNIT. Kate Stewart makes the decision that they only way to defeat them is to destroy London itself. The Doctors have to utilise the same technology to cross time and immobilise the threat before making a return to Gallifrey to support the War Doctor in his final act of ending the Time War. However, it is Clara who persuades the Doctor to come up with another solution and, calling on all of his past incarnations he succeeds in not destroying Gallifrey but hiding it, so that in the Daleks' final attack they annihilate themselves.

The Doctors prepare to return to their own timestreams, and in doing so neither the War Doctor or the Tenth will remember the events that led to the saving of Gallifrey and will continue to be consumed by their guilt, so much so that the War Doctor will refuse to take on the name of Doctor. Only the Eleventh is still aware, and after a final conversation with the enigmatic gallery curator (Tom Baker) he realises that he is the only one who can track down and restore Gallifrey.

The Day Of The Doctor, written by Steven Moffat and directed by Nick Hurran, was filmed in South Wales and London between March - May 2013. The 75 minute 3D special was broadcast on BBC One on Saturday 23rd November and was also simulcast by 94 countries, streamed online and projected into cinemas worldwide, making it the largest ever simulcast of a TV drama.