I'm The Doctor, the Definite Article Quiz

One of the show's original three companions, Susan Foreman (played by Carole Ann Ford) is introduced as the Doctor's granddaughter in the pilot, "An Unearthly Child". Two of her teachers, Ian Chesterton and Barbara Wright, have some concerns about Susan and go to visit her at home - to a very strange address at a junkyard. Susan is then told that due to this drawing attention to them, they'll have to move on again - and in the ensuing chaos, Ian and Barbara get swept up unwillingly into travelling with them. William Hartnell is the Doctor in this era.

Introduced in the second story of Patrick Troughton's era, "The Highlanders", and continuing to the end of his era, Jamie (played by Frazer Hines) is the show's longest-serving companion, having appeared in over 100 episodes of the show. Jamie is from 1746 and first meets the Doctor during the Battle of Culloden and a lot of the time serves as the muscle of his era while the Doctor is, of course, the brains (alongside later companion Zoe).

Another companion from a historical setting, Victoria Waterfield (played by Deborah Watling) also travels with the Doctor (still played by Patrick Troughton). Fittingly given her name, she is from the Victorian era, and first appears in "The Evil of the Daleks". During that serial, her father unfortunately perishes, and the Doctor and Jamie take her with them to ensure her safety.

At first glance, Jo (played by Katy Manning) and the Doctor (now played by Jon Pertwee) seem to be very incompatible personalities, and the Doctor certainly initially takes a dim view of her. It doesn't help that she's such a stark contrast to his previous companion, Liz Shaw, who was as brilliant as he was.

However, her bravery and character won him over, and despite his prickly exterior, it was obvious that he was fond of her as she assisted him at UNIT. She initially appears in "Terror of the Autons".

Probably the most well-known of the companions in the original series, Sarah Jane Smith (played by Elisabeth Sladen) actually first appears in "The Time Warrior", with the 3rd Doctor. She is mostly associated with the 4th Doctor (Tom Baker), however. She is a journalist who isn't afraid to speak her mind, is brave and is openly a feminist.

She made an appearance in the modern-day series of "Doctor Who", too, as well as being the star of "The Sarah Jane Adventures" on CBBC with her own group of young helpers.

Romana herself is also a Time Lord, but that doesn't stop her from also being a companion to the Doctor. Originally appearing in "The Ribos Operation" and portrayed by Mary Tamm, she later regenerates and is thereafter portrayed by Lalla Ward as of "Destiny of the Daleks". Like the Doctor, Romana also has a very high opinion of her own intellect, especially in contrast to other people's.

Interestingly, Tom Baker and Lalla Ward actually got married in 1980, not long after they starred together in "Doctor Who", but it only lasted for 16 months before they got divorced.

Another companion who fills the mould of being very intelligent, young Adric (played by Matthew Waterhouse) first appears in "Full Circle", with the fourth Doctor. However, he's more associated with Peter Davison. The most notable thing about Adric as a companion is his surprising death in "Earthshock", showing that the newer era of the show was not afraid to do this.

Perhaps not one of the most talked-about companions, and not the longest-serving with Davison either (that would be Tegan Jovanka), Turlough (played by Mark Strickson) is fairly unique as a companion. For one, he isn't human, for all that when we meet him in "Mawdryn Undead", he's in a boy's school playing at being human, but also causing trouble.

The Black Guardian commands that, in order to be able to return home, he must kill the Doctor: Turlough ends up becoming a companion with this goal in mind.

However, he fails to kill the Doctor, and by the end of "Enlightenment", he's made the choice that he does not want to do this.

Played by Bonnie Langford, Mel first appears in "Trial of a Time Lord" as a companion to the 6th Doctor, Colin Baker. By this point, he's mellowed somewhat from the rather frightening character he initially appears as, very different from the much milder-mannered Peter Davison so she doesn't get as much of a shock as her immediate predecessor Peri.

Another of the more iconic companions, Ace (as she preferred to be known) worked alongside the 7th Doctor, Sylvester McCoy. Played by Sophie Aldred, she initially appeared in "Dragonfire" and travelled with him until the series was cancelled. She refers to the Doctor as the "Professor" instead.

She's most noteworthy for her cheerful interest in nitro-9 explosives and her more violent solutions to problems, such as hitting a Dalek with a baseball bat. Many Doctor Who companions were considered to fall into damsel-in-distress stereotypes, but Ace was very much an action girl, and much loved for that.