Daleks' timeline

By several accounts, the Dalek species had a unique timeline which was heavily interfered with on multiple occasions from conflicting accounts of their origins to being further complicated by the Last Great Time War. (TV: Genesis of the Daleks, PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe, Dalek Combat Training Manual)

The Eighth Doctor found Dalek history a difficult thing to remember because it was always changing. (PROSE: Alien Bodies) A member of Faction Paradox thought that this was because the Doctor "tricked the Dalek Empire into tangling their timeline so bad that their history collapsed under the weight of the paradoxes". (PROSE: Unnatural History) Historians who studied the Daleks noted the Daleks themselves often dipped back into their own past in their attempts to rewrite past failures, (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe) and not even the Time Lords could organise all accounts of Dalek history together. (PROSE: Dalek Combat Training Manual) The Tenth Doctor reflected that "Dalek history was confusing enough before the Time War." (PROSE: Prisoner of the Daleks)