Why Every Classic Companion Left Doctor Who
10. Mary Tamm - Romana
Mary Tamm played the Doctor's Time Lady companion Romana in the Key to Time season, but found herself experiencing a similar problem to her predecessors Carole Ann Ford and Caroline John. The role of Romana was pitched to Mary Tamm as a genius, an equal to the Doctor rather than the traditional "assistant".
Unfortunately, the character quickly became reduced to being in thrall to the Doctor, or getting captured by the villains-of-the-week. Disappointed at this squandering of Romana's potential, Mary Tamm decided to leave the role at the end of the Key to Time season. Much like Caroline John before her, this decision meant that a hasty exit had to be conceived for the top of the next season.