When school teachers Ian Chasterton (William Russell) and Barbara Wright (Jacqueline Hill) discover Susan Foreman (Carole Ann Ford) is not just a peculiar teenager but in fact an alien from a distant planet, they are both brought on an epic journey through space and time with Susan and her eccentric grandfather known only as The Doctor (William Hartnell). But throughout all their adventures they still have a longing to return home.
Most actors on TV in the early 60’s were either veterans sick of being typecast or young, eager drama school graduates, unemployed and more than willing to jump at any role turned down by snobbish theatre thespians. This combination made for engaging and emotional performances with a level of humanity not seen on either the stage or cinema. Doctor Who was no exception and representing that humanity were William Russell and Jacqueline Hill. Ian Chesterton, the science teacher was the brave, quick witted hero with a good heart. Barbara Wright was a history teacher who exhibited the compassion, intelligence and level headedness needed for their transdimensional journey. Exactly the kind of qualities any weary time wanderer could wish for in a companion. Russell and Hill brought forth those qualities beautifully. 
Without resorting to wordy monologues or emotional manipulation, their graceful, understated charisma took us further into their world and gave it life. You couldn’t ask for more lovely acting.
The two teachers have some great relationships with the TARDIS crew. First and foremost there’s The Doctor. Despite their adventures, they are still wandering aimlessly through the time vortex and have not been able to reach home. They feel annoyed at the Doctor and at times seem not to like him. He is after all supposed to be in control of the TARDIS. The Doctor himself is reluctant to even let himself be liked, especially by two intruding humans who couldn’t possibly comprehend who he is or why he travels. Eventually, they grow to rely on each other and maintain a strong level of trust. This helps bring out the lighter side of The Doctor too and he gradually becomes less cantankerous the more he gets to know them. Ian and Barbara are far more friendly with Susan and share a unique bond with her.
Though time travel is an everyday concept to her, she is still their student and they are responsible for her. But even outside of the TARDIS they still rather like her. She has charm and brilliance which made her a talking point for the teachers at Coal Hill School yet her aloofness and 
awful grades are what made Ian and Barbara so concerned about her in the first place. They are very kind to Susan and she in turn comes to see them as true friends and not just teachers. But the best friendship Ian and Barbara share is with each other. Right from the beginning they are clearly more than just professional colleagues. While nothing romantic between them is depicted on screen they are always shown to be great pals. This would explain why they never seemed to get too angry at The Doctor. Even if they couldn’t get home, they still had each other through it all.
Unfortunately, as the show went on, cracks began to appear. The Doctor and three companions is a lot to keep up for several four, sometimes six part adventures and while there were still some fine elements, the ratio of quality episodes to filler was less than satisfactory. This inevitably had an impact on the characters who were often just left on the TARDIS or kidnapped just to get them out of the way. When Susan left the TARDIS and Vicki arrived, there was a definite change in the dynamic but it wasn’t the same. Ian and Barbara had a connection with Susan they just couldn’t reach with Vicki, who wouldn’t really flourish as a character until the next series.
In 1965 Ian and Barbara’s last adventure, The Chase was aired. Their farewell scene, like all the good ones, is a beautiful collage of emotions played so brilliantly by the cast that there’s not a single hint of clutter. Ian, sick of travelling and failed attempts to get home, has one last great argument with The Doctor. Barbara tries to convince The Doctor using her usual care and gentle firmness. The Doctor feels slightly jilted by their decision but his indignant tone is a front for how sad he really feels. Vicki is the voice of reason and while she grew very fond of them, she knows that it is their decision to make. There are no regrets, no tears and no anxieties. They simply share a giggle about their past two years and move on. With so much heavy-handedness and characters pining over each other in recent years, it’s always nice to see that there are better ways to do it. Upon their safe return 
The Doctor simply says “I shall miss them. Yes, I shall miss them, silly old fusspots. Come along, my dear, it’s time we were off.”
We never saw them again. For the rest of the original run neither Ian nor Barbara made an appearance and the death of Jacqueline Hill in 1993 meant that any attempt at a reunion in the future would be sadly impossible.
So, what became of Ian and Barbara? Several scenarios of questionable canon have been published but interestingly enough, almost all of them depict them as a married couple. Then came that wonderful episode of The Sarah Jane Adventures called ‘Death of The Doctor’. Sarah Jane, when asked if she knew what happened to any of The Doctor’s other companions, says with a smile “Ian and Barbara Chesterton”. I cheered. Yes! They did indeed get married and we now know they remained happy after all their wild adventures. A perfect ending for a perfect couple.
