Susan Foreman's father

By some accounts, there was such a person as Susan Foreman's father, although his identity, fate, and relationship to the Doctor depended on accounts.

In an account where Barbara Wright was Susan's tutor, (PROSE: Doctor Who in an Exciting Adventure with the Daleks) rather than her teacher at Coal Hill School, (TV: An Unearthly Child) Susan told Barbara that she "hadn't seen her mother and father in a long time". (PROSE: Doctor Who in an Exciting Adventure with the Daleks)

According to one account, Susan's father was Time Lord of the first rank and a Cardinal. He was the eldest of the thirteen children of the Doctor and Patience. He lived in the House of Blyledge with his family. On the day that his wife was giving birth, Lord President Rassilon sent guards to terminate the pregnancy, as it had been decreed that only the loom-born could inherit the legacy of Rassilon, but the First Doctor saved Susan and Patience. (PROSE: Cold Fusion)

In an account where the Other was Susan's grandfather instead of the Doctor, and Susan therefore grew up in ancient Gallifreyan times, Susan's father died in battle on one of Rassilon's bowships during the Eternal War. (PROSE: Lungbarrow)

According to yet another account, Susan's parents owned a concept shop on Gallifrey, and Susan lived there when she was an infant. They themselves suggested that the First Doctor take her to Earth. However, this was only one of multiple coexisting pasts for Susan, alongside her being "Lady Larn" or the Other's granddaughter. (PROSE:  A Rough Guide)

According to some accounts, Susan was the daughter of the Lord President of Gallifrey. (PROSE: A Brief History of Time Lords, TV: Hell Bent) One account says that Pandad VII was Lord President of Gallifrey around the time the First Doctor and Susan left Gallifrey. President Pandad VII ordered Lord Burner Braxiatel to burn "an old man" and "his granddaughter" from history. He disobeyed this order and the intended victims stole a TARDIS and fled Gallifrey. The very same day, President Pandad died when a power relay in his office overloaded; an inquiry headed by Braxiatel found that this was an accident. (AUDIO: Disassembled)

According to a conflicting account, Slann was Lord President of Gallifrey during the time the First Doctor and Lady Larn, a descendant of Rassilon, left Gallifrey. He was assassinated by the Master shortly after. (PROSE: Birth of a Renegade) Curiously, another account spoke of Pandad IV as a President postdating the Doctor's departure from Gallifrey. (PROSE: The Legacy of Gallifrey)

Behind the scenes

 * The unproduced television story The Son of Doctor Who would have introduced a son of the First Doctor who was also played by William Hartnell, nearly setting a precedent at the beginning of Doctor Who history of the Doctor having a doppelganger son. The casting of Fifth Doctor actor Peter Davison as Susan's father in the audio adaptation of Cold Fusion once more suggests the Doctor's son to uncannily resemble his father.