Barbara Wright was teaching history at Coal Hill School in London in 1963, working with science teacher Ian Chesterton. One of their students, Susan Foreman, shows an unusually advanced knowledge of science and history, but a rudimentary knowledge of other subjects. In an attempt to learn more about this "unearthly child", Barbara and Ian follow Susan home to a junkyard, where they hear her voice coming from what appears to be a police box. During a confrontation with her grandfather, the Doctor, Barbara rushes in to the police box, only to discover that its exterior hides the much larger interior of the TARDIS, revealing the vehicle for the first time and making Barbara the first human to step aboard.
At first a reluctant traveller in time and space, the strong-willed Barbara becomes more adventurous, while providing a maternal figure to Susan and subsequently Vicki. She is frequently the only person willing to stand up to the First Doctor's cantankerous outbursts with firmness and logic. A chemistry between her and Ian is also evident, although the nature of their relationship is never fully clarified in the television series.
Although mutually respectful and increasingly affectionate, the relationship between the Doctor and Barbara is often tested by their opposing viewpoints. In The Aztecs, Barbara is mistaken for the reincarnation of a high priest, Yetaxa, after they find her in possession of his bracelet. Barbara seizes this opportunity to change the course of history, and tries to persuade the Aztecs to abandon human sacrifice, so that by the time Hernan Cortes - who overthrew the Aztec empire - lands he will find a glorious civilisation. The Doctor warns Barbara that she cannot rewrite history, but his protests fall on deaf ears. Barbara fails and, although she has influenced some Aztecs, history remains on course.
As well as exploring alien planets, Barbara visits several eras of Earth's history, including the Roman Empire during the time of Nero, Palestine during the Third Crusade, the Himalayas in the 13th Century, and a post-apocalyptic London in the 22nd Century.
After the TARDIS is chased through time and space by the Daleks to the planet Mechanus, where a conflict destroys the pursuing faction of Daleks, Barbara suggests to Ian they use the abandoned Dalek time machine to get home. The Doctor is furious and tries to persuade them to stay with him by suggesting the journey might kill them, but the two teachers had made up their minds. After an emotional farewell to the Doctor and Vicki, Barbara and Ian are returned to London, albeit two years after their disappearance. Back on the TARDIS, the Doctor uses the time-space visualiser to check they have returned safely, and tells Vicki how much he will miss them.
