And another thing: Mickey is the first non-Caucasian companion in the history of the TV show (although the Doctor’s first black companion was actually Sharon Davies who appeared the Doctor Who Weekly comic strips from 1980 to 1981).

played by FREEMA AGYEMAN

First regular Doctor Who appearance: Smith and Jones (2007)

Final regular Doctor Who appearance: Journey’s End (2008)

Final guest Doctor Who appearance: The End of Time, Part Two (2010)

Before Doctor Who, Freema Agyeman had made appearances in The Bill, Casualty @ Holby City and, most notably, as Lola Wise in Crossroads. Martha would go on to appear in Torchwood while Agyeman would become one of the stars of Law and Order UK in 2009 and the Sex and the City prequel The Carrie Diaries in 2013.

Martha Jones was training as a doctor at Royal Hope Hospital when it was transported to the Moon by the Judoon. Attracted to the Doctor from their first meeting, Martha eagerly joined the Time Lord on his travels but soon realised that he would never feel the same way. Exceptionally compassionate and loyal, Martha was repeatedly asked to go the extra mile, watching over him when he became human or travelling the world for a year after the Master conquered the Earth. After leaving the Doctor, Martha was soon recruited to UNIT and finally achieved her doctorate.

And another thing: Freema Agyeman also appeared in the 2008 remake of Terry Nation’s Survivors.

played by JOHN BARROWMAN

First regular Doctor Who appearance: The Empty Child (2005)

Final regular Doctor Who appearance: Journey’s End (2008)

Final guest Doctor Who appearance: The End of Time, Part Two (2010)

Born in Scotland, John Barrowman was brought up in the USA, where he studied performing arts in San Diego – training that would bring him back to London and his West End stage debut in the musical Anything Goes. A skilled singer and dancer, Barrowman has played many stage roles, but his casting as Captain Jack Harkness in Doctor Who in 2005 turned him into an international screen star. As the lead in Doctor Who spin-off Torchwood, the actor has amassed a huge fan following, and has since appeared in TV series on both sides of the Atlantic including Hustle, Desperate Housewives and Arrow, released bestselling albums and books, and presented the Saturday night BBC entertainment show Tonight’s the Night.

Captain Jack Harkness is a conman, rogue and 51st-century Casanova in one. Killed by the Daleks on the Game Station, the former Time Agent was brought back to life by Rose’s Vortex powers, and this left him unable to die. Jack’s adventures throughout time brought him to Cardiff and command of Torchwood, where he continued to defend the Earth.

And another thing: Jack came from the Boeshane Peninsula, where he claims his nickname was ‘the Face of Boe’.

played by CATHERINE TATE

First Doctor Who appearance: The Runaway Bride (2006)

First regular Doctor Who appearance: Partners in Crime (2008)

Final regular Doctor Who appearance: Journey’s End (2008)

Last guest Doctor Who appearance: The End of Time, Part Two (2010)

Catherine Tate is one of Britain’s foremost character actors, with the award-winning Catherine Tate Show showcasing her talent for character comedy with creations such as the foul-mouthed Nan and schoolgirl Lauren. Following her guest appearance as Donna Noble in the 2006 Doctor Who Christmas special, Catherine was tempted back for a full-time TARDIS residency in 2008. She has since appeared in the film Gulliver’s Travels (2010) and in the American version of The Office.

Donna Noble used to be oblivious to the world around her – she was more excited about a new flavour of crisps than a spaceship hanging over London on Christmas Day. Then she met the Doctor. Long after her first adventure in the TARDIS, Donna finally tracked the Doctor down and they travelled the universe together, encountering Adipose, Pyroviles, Vespiforms and Agatha Christie – but not Noddy. Without Donna, Davros and the Daleks would have destroyed reality itself, but there was a price. If Donna ever remembers her adventures with the Doctor, it will destroy her mind.

And another thing: In 2011, Catherine Tate and David Tennant reunited in the Wyndham’s Theatre’s production of Much Ado About Nothing.

THE TENTH DOCTOR’S RULES FOR COMPANIONS

Rule 1: ‘Don’t wander off.’

HELLO SWEETIE

‘Shall we do diaries, then? Where are we this time?’

River Song, Silence in the Library

We need to talk about River Song, the most timey-wimey of the Doctor’s, erm, friends. She’s not exactly a companion, but her significance in the Doctor’s lives is vast. As time travellers, their shared encounters are experienced out of order, which can make it all a bit confusing – for everybody, including the Doctor. Here, in full, is the timeline of River Song, aka Melody Pond, aka Melody Malone, aka the Doctor’s other half. Well, as far as we can tell at the moment, anyway.

Born as Melody Pond on Demon’s Run, the daughter of Amy and Rory (52nd century – A Good Man Goes to War)

Kidnapped by Madame Kovarian and raised at Graystark Hall Orphanage on Earth by the Silence as a weapon to kill the Doctor (1960s – Day of the Moon)

Shot as a young girl by Amy Pond in a Florida warehouse (1969 – The Impossible Astronaut)

Regenerates for the first time in a back alley in New York City (1970 – Day of the Moon)

Travels to Leadworth and, calling herself Mels, befriends young Amy and Rory so she can grow up with them (1990s–2000s – Let’s Kill Hitler)

Forces the Doctor to take her back to Berlin, 1938, to kill Adolf Hitler (2011 – Let’s Kill Hitler)

Shot by Hitler, Mels regenerates into the woman who will become River Song (1938 – Let’s Kill Hitler)

Attempting to complete the mission she was trained for, River tries to poison the Doctor. Shortly before the Doctor’s death, she uses her remaining regenerations to save him (1938 – Let’s Kill Hitler)

Taken by the Doctor, Amy and Rory to the best hospital in the universe. When she wakes, she finds a police box-shaped diary next to her bed (52nd century – Let’s Kill Hitler)

Enrols to study archaeology at the Luna University, gaining a Doctorate (52nd century – Let’s Kill Hitler)

Madame Kovarian returns, forcing River to complete the task she was trained to do (52nd century – Closing Time)

At Lake Silencio, while wearing the NASA spacesuit, River fails to kill the Doctor (22 April 2011 – The Wedding of River Song)

This leads to all sorts of timey-wimey problems, involving Emperor Churchill, secret agents, the Silence and pyramids (22 April 2011, probably – The Wedding of River Song)

River marries the Doctor – possibly (22 April 2011 – The Wedding of River Song)

The timeline is put right and River kills the Doctor at Lake Silencio (we’ll explain later) (22 April 2011 – The Wedding of River Song)