Doctor Who: Every Companion Ranked Worst To Best

The longest-serving companion of the modern era of Doctor Who, the story of how Clara came to be the Doctor's companion is a complicated one. The Doctor first met her doppelgänger "Oswin" in the Asylum, a prison filled with hundreds of psychotic Daleks. The only problem was that this version of Clara turned to be a self-aware Dalek that was being kept prisoner so the Dalek species could exploit her genius-level intelligence. Soon enough, another double of Clara appeared in Victorian London, accompanying the Eleventh Doctor for one adventure before dying again. Things were not going to be easy for Clara and the Doctor.

Eventually, the Doctor found the original Clara Oswald, and after a while, discovered that the reason that different versions of her kept cropping up all around the universe was because she entered the Doctor's personal timestream, sending fragments of herself throughout the Doctor's life and interacting with all of his previous incarnations (as you do).

As a companion, Clara was unwavering in her enthusiasm for the adventures she shared with the Eleventh and Twelfth Doctors, the latter of which she spent the most time with. Even when the Doctor was being unreasonable or irrational, Clara was always on-hand to make sure that he was grounded and able to help those around him without them losing all their confidence in his ability to save the day. As spirited as she was intelligent, Clara was the quintessential companion that was able to do things her way when she recognised that the Doctor's arrogance was getting the better than him.

Having featured on the show for close to 4 years (a record for the modern era of the show), Clara was the gold standard when it came to being an ally of the Doctor's.