Why Every Modern Companion Left Doctor Who

14. Billie Piper - Rose Tyler

Billie Piper helped make Doctor Who an overnight sensation way back in 2005, but it was that popularity that played a small part in her decision to leave. Reflecting on Doctor Who in an appearance on Desert Island Discs back in 2019, Piper said that:

"It made me really famous again in that sort of mainstream fame way that I find really uncomfortable."

This fame and the increased public profile was also potentially damaging to her burgeoning career as an actor. And so to avoid typecasting - and the harsh glare of the limelight that Doctor Who shines on a person - Piper decided to leave the show behind after two years to pursue other acting roles in other popular shows like Secret Diary of a Call Girl and, more recently, Wednesday. 

Of course, we know that when Billie left the role in 2006, she had already agreed to return for season 4. Then she came back in 2010 for David Tennant's final farewell, and again in 2013 for Day of the Doctor, then finally appeared as the 16th Doctor/Rose/Bad Wolf in the closing moments of The Reality War.