Charles Francis Xavier was born the son of nuclear researcher Brian Xavier and his wife, Sharon. Following her husband’s accidental death, Sharon married Brain’s colleague, Kurt Marko. Cain, Kurt’s son by a previous marriage, came to live at the Xavier’s Westchester mansion shortly thereafter. A cruel and spiteful boy, he bullied his new stepbrother. As punishment, his father secretly beat him – and young Charles felt his sibling’s pain firsthand thanks to the emergence or his mutant telepathic powers. Following their mother’s death, a fire in the family home took Kurt’s life, leaving the stepbrothers alone.
By the time he graduated high school, Charles was completely bald as a side effect of his mutant nature. He entered Bard College in New York at age 16 and earned his bachelor’s degree in biology within two years. He was then accepted into the graduate-studies program at England’s prestigious Oxford University, where he earned degrees in genetics and biophysics. There, Charles met and fell in love with a young Scotswoman named Moira Kinross. Their passionate discussions on the subject of genetic mutation gave way to romance, and they planned to marry. Their only obstacle was Moira’s former boyfriend, Joe MacTaggert, a lance corporal in the Royal Marines and a bully, just like Cain. In Joe’s eyes, Charles was a good-for-nothing intellectual, so Charles enlisted in the military after completing his studies at Oxford to validate himself in terms his rival would understand.
Charles quickly became something of a legend in the area of search and rescue thanks to his mutant abilities.
Attached to the same unit as his stepbrother, Charles was present when Cain deserted under fire during a mission in Asia. Following him in the hope of convincing him to return to their unit, Charles witnessed Cain’s discovery of the mystical Ruby of Cuttorak and his transformation into the superhuman
Juggernaut. Charles escaped the subsequent cave-in, mistakenly believing his stepbrother was dead.
Later, Charles was devastated when Moira broke off their engagement without explanation. He left the Army and began traveling the world. In Cairo, Egypt, he encountered Amahl Farouk, a mutant capable of summoning forth the darkness in the souls of others. This confrontation led to Charles decision to devote his life to protecting humanity from evil mutants and saving innocent mutants from human oppression.
Charles next traveled to Israel, where he fell in love with Israeli diplomat Gabrielle Haller. He also befriended a fellow drifter named Erik Magnus Lehnsherr, a fellow mutant who would become his greatest enemy: Magneto, self-styled master of magnetism. Whilst Charles optimistically believed that humans and mutants could coexist, the Jewish Magnus foresaw mutants as the new minority to be persecuted and hunted because of their differences. Together, the pair prevented the nefarious Baron Von Strucker from launching his terrorist group Hydra on an unsuspecting world. Magnus departed with Strucker’s gold, and upon departing Israel himself, Charles was unaware that Haller was pregnant with his son, David.
En route to the United States, Charles encountered the alien scout Lucifer in the Himalayas. To prevent any interference in his race’s planned invasion of Earth, Lucifer dropped a massive stone block on Charles, crippling his legs. In desperation, Charles called out with his mental powers and touched the mind of a young mutant named Tessa who was operating as a mercenary in the neighboring Hindu Kush mountains.