Alex Campbell

Alexander David Campbell was the son of Susan Foreman and the great-grandson of the Doctor.

Early life
Alex was the only biological child of Susan and David Campbell. He was born ten years after the Dalek occuption of Earth. Susan and David did not tell him about his true heritage, as they believed it would make it hard for him to live his life on Earth. (AUDIO: An Earthly Child).

Meeting the Doctor
After his father's death, Alex grew rebellious. He joined youth groups opposed to the new Earth Council. When he was seventeen, he met his great-grandfather, who saved him from the Guldreasi and told him of his origins. The Doctor wanted Alex to have an education on Gallifrey to fulfill his full academic potential. However, Alex saw Earth as his home and decided to stay with his mother. (AUDIO: An Earthly Child)

Six months later, Alex had Christmas dinner in the TARDIS with his mother, the Doctor and Lucie Miller. Although the Doctor was his great-grandfather, he came to refer to him simply as "Granddad." During this visit, the Doctor analysed Alex's DNA and discovered that Gallifreyan genes constituted only 7% of his genome. Unlike full blooded Time Lords, he was not telepathic and could not regenerate. The Doctor intended to give the TARDIS to Alex at some point, though only after he had travelled with him. However, Alex decided to go on a grand tour of Europe with Lucie instead. (AUDIO: Relative Dimensions)

During the Daleks' second attempt to conquer Earth, Alex fronted a resistance with Lucie and saved the Doctor from being blown up in a Dalek saucer. Alex was later killed by a Dalek while helping Lucie plant a bomb to destroy the Daleks. (AUDIO: Lucie Miller / To the Death)