Ian Chesterton (William Russell)
A teacher at Coal Hill School, Ian encountered the Doctor when he visited the home of one of his pupils, Susan Foreman, with his colleague, Barbara Wright. Fearing that the teachers would reveal his secret, Susan's "Grandfather" the Doctor kidnapped them, beginning a series of exciting adventures.
Ian's speciality was science, but his skills as a diplomat were also useful. He was often called upon to play peacemaker, and many times saved the lives of his fellow travellers. His often stormy relationship with the cantankerous Time Lord ended when he and Barbara finally returned to Earth in an abandoned Dalek time capsule.