Before Charles Xavier and Erik Lensherr took the names Professor X and
Magneto, they were two young men discovering their powers for the first
time. Before they were archenemies, they were closest of friends,
working together, with other Mutants (some familiar, some new), to stop
the greatest threat the world has ever known. In the process, a rift
between them opened, which began the eternal war between Magneto's
Brotherhood and Professor X's X-MEN.