When they were first created in the 60s, there was no implied connection between Magneto and Professor X, other than the fact that they were both the leaders of opposing mutant groups. But then when Chris Claremont started writing the X-Men, he developed a backstory for the two men that showed they were once friends in the past. When the two were young men, they met in Israel in a clinic for Holocaust survivors and engaged in lengthy discussions and debates about what would happen if mankind were faced with a race of super-powered humans. After revealing their powers to each other and realizing their beliefs were incompatible, they parted ways. Since then, the relationship between Professor X and Magneto, and the ideological differences that separate them, has long served as the backbone of the X-Men comics. Even when theyve been depicted as bitter enemies, theres always been an undercurrent of mutual respect between the two characters. During a period when he had to go into space in order to heal from grievous injuries, Xavier even left his school and students in the care of a reformed Magneto. Its also been a heavy focus of the films. Although Xavier and Magneto had few scenes together in the early X-Men films, their political views influenced the original trilogy in significant ways. The new slate of films that began with X-Men: First Class and continues with X-Men: Days of Future Past puts even more focus on the bromance, with Xavier and Magneto serving as the major characters.
Percival Constantine is the author of several novels and short stories, including the Vanguard superhero series, and regularly writes and comments on movies, comics, and other pop culture. More information can be found at his website, PercivalConstantine.com