Barbara Wright is a history teacher at the Coal Hill School, working with science teacher Ian Chesterton. One of their students, Susan Foreman, the granddaughter of the Doctor, shows an unusually advanced knowledge of science and history. Attempting to solve the mystery of this "unearthly child", Ian and Barbara follow Susan back to a junkyard, where they hear her voice coming from what appears to be a police box. When they investigate further, they discover that the police box exterior hides the much larger interior of a time machine known as the TARDIS, and are whisked away on an adventure in time and space with the Doctor and Susan.
Barbara is a strong-willed woman and provides a maternal figure to Susan. She is frequently the only person who can stand up to the First Doctor's cantankerous personality. The chemistry between Ian and herself is also evident, although the nature of their relationship is never made explicit in the television series.
In the serial The Aztecs, Barbara is hailed as the reincarnation of the ancient high priest Yetaxa by the Aztec civilization. Despite the Doctor's protests that she cannot change history, she attempts to turn the Aztecs away from their practice of human sacrifice. In The Reign of Terror, she establishes a friendship with Leon Colbert and is distraught when he is killed. After many travels, Ian and Barbara eventually use a Dalek time machine to get home, albeit two years after their disappearance and presumably with much explaining to do to their friends and families.