The Doctor's reality (An Unearthly Child)

In Auld Mortality's universe, the Doctor asked Susan to come with him as he made his escape from Gallifrey, and the Possibility Generator detected several branching timelines in which she agreed, (AUDIO: Auld Mortality) including one where the Doctor and Susan came to live in Barnes Common (PROSE: Doctor Who in an Exciting Adventure with the Daleks) and one where the Doctor and Susan came to live in Totter's Lane. (TV: An Unearthly Child)

However, other parallel possibilities involved Susan saying no, (AUDIO: Auld Mortality) and further accounts showed the Doctor living a parallel version of the First Doctor's life in which Susan declined and the Doctor subsequently never met Ian Chesterton and Barbara Wright. (AUDIO: A Storm of Angels, PROSE: The Innocents)

During the Last Great Time War, the Barber-Surgeon met a "version" of the Doctor who related that they had met Ian and Barbara following a car crash in Barnes Common. The War Doctor, however, related the version of events in the Totter's Lane junkyard. Upon being told of the version involving Ian's car breaking down, the War Doctor declared "that never happened", which the Barber-Surgeon replied to by noting "everything's happened somewhere". (AUDIO: The Horror) The Time Lords themselves were aware of multiple, alternative accounts of the Doctor's first encounter with the Daleks, all of which involved Ian Chesterton. (AUDIO: Sphere of Influence, PROSE: Dalek Combat Training Manual)

From what it described as "film evidence", the Dalek Survival Guide was aware of an alternative version of the Skaro City Daleks and the Dalek Invasion Force (PROSE: Dalek Survival Guide) who were defeated by the version of Dr. Who who had a niece called Louise and a granddaughter called Barbara in addition to his granddaughter Susan. (TV: Dr. Who and the Daleks, Daleks' Invasion Earth 2150 A.D.) The guide identified these Daleks as hailing from a "version of history B" relative to the First Doctor's "version of history A". (PROSE: Dalek Survival Guide)

Behind the scenes

 * In an interview in DWM 490, Steven Moffat proposed that Dr. Who recklessly altering Time to change the outcome of the smash and grab at the end of Daleks' Invasion Earth 2150 A.D. caused him to accidentally restart his universe, rewriting himself into a Time Lord and losing his family name.