Stories occurring prior or parallel to X-Men #1 in September 1963. A part of Crushing Krisis’s Collecting X-Men: A Definitive Guide. Last updated January 2013.
Rise of Apocalypse #1-4
Collected: Rise of Apocalypse TPB
When: Occurs in ancient Egypt concurrent with events depicted in the time-travel story in Fantastic Four #19. Starts just after Apocalypse’s birth and continues through his rise to power – about 18 years of story.
Before the Fantastic Four: Ben Grimm & Logan #1-3
Collected: Not collected
When: This is set prior to Wolverine’s adamantium or Benn Grimm becoming The Thing, and during the Cold War with USSR Russia.
First X-Men #1-5
Collected: First X-Men hardcover and TPB (pending solicitation)
When: This retcon story occurs in the 70s in Marvel’s modern sliding timescale, but in terms of pre-dating X-Men #1 it is more than a few years – Namor is homeless and without memories, Xavier is still at University in England, and Magneto is hunting Nazis in South America. It ends with characters moving towards their appearances in X-Men #1, but still several years away.
X-Men Origins: Various Titles
Collected: X-Men Origins I oversized hardcover and TPB
Collected: X-Men Origins II oversized hardcover and TPB
When: Various times prior to or concurrent with X-Men #1-65. Because some of these origins pre-date X-Men #1, I place these collections in the Pre-X-Men era. However some origins – particularly Gambit’s – occur much later and involve characters and situations set up by prior X-Men stories. Another reading order option for these issues would be to read them just before or after the debut issue of each of their characters.