Why Every Classic Companion Left Doctor Who

Jacqueline Hill played Barbara Wright in 76 episodes of Doctor Who between 1963 and 1965. Without Barbara convincing Ian to investigate Totter's Lane, we might never have got the Doctor that we know and love. Hill was terrific as Barbara, never a screaming Doctor Who girl, proving herself to be capable of standing up to both the Daleks and the Doctor.

Details are vague as to why Hill made the decision to leave in 1965, however given that she quit acting soon after to start a family with husband Alvin Rakoff, it's likely that this played a part in her departure from Doctor Who. 

Jacqueline Hill returned to acting in 1979, and in 1980 was cast as Lexa in the Tom Baker serial Meglos.