Personality: Charles Xavier is a stern and reserved man whose force of personality makes him the master of any debate he enters. He is dedicated to the ideal of peaceful co-existence between mutants and humans, and he labours tirelessly to achieve this goal. He cares for all of his X-Men and would risk his life to do anything for them. He is aware that there are tensions between some of his wards, and that life in the mansion has become crowded, but he is confident in all of their abilities to deal with the changes.

Special skills and abilities: Leading authority on genetics, mutation, and psionic powers, considerable expertise in other life sciences, highly talented in devising equipment for utilizing and enhancing psionic powers

Known superhuman powers: Professor X ordinarily possesses vast psionic powers, including telepathy; the ability to induce in others mental illusions, temporary mental or physical paralysis, and loss of specific memories or total amnesia; the projection of "mental bolts" to stun or render a person unconscious; astral projection; and the ability to sense other superhuman mutants within a small radius.

Special limitations: Part of spine shattered, confined to wheelchair.

Charles' telepathic powers began emerging when he was still a boy, and as he grew older he learned to control them. A brilliant student, he entered graduate studies at England's Oxford University, where he met and fell in love with a young Scotswoman named Moira MacTaggert. They planned to be married, but after finishing his work at Oxford, Xavier was drafted and sent to Asia. There Xavier and Cain Marko served in the same unit. Xavier witnessed how Marko found the mystical ruby in the temple of Cyttorak that transformed him into the superhuman Juggernaut.

Deeply depressed when Moira broke off their engagement without explanation, Xavier began traveling abroad after leaving the army. While in Cairo, Egypt he battled Amahl Farouk, the Shadow King, the first evil mutant he had ever met. This meeting led to Xavier's decision to devote his life to protecting humanity from evil mutants and safeguarding innocent mutants from human oppression.

Xavier next went to Israel, where he fell in love with Gabrielle Haller and became friends with a man calling himself Erik Magnus Lehnsherr. Lehnsherr would years later become his greatest enemy and rival, Magneto. Xavier was unaware when he left Israel that Haller was pregnant with his son, who would become the mutant known as Legion.

Against an alien calling himself Lucifer, the advance scout for an invasion by his race. In retaliation, Lucifer dropped a huge stone block on Xavier, crippling his legs.

Whilst at University in London, he renewed his friendship with Moira MacTaggert, who was now a renowned geneticist, and they began discussing the idea of founding a school for mutants. Xavier's first student was the 11-year-old Jean Grey, who had been traumatized when she telepathically experienced the emotions of a dying friend. Xavier helped Jean recover and taught her to use her telekinetic powers.

Xavier later met with Fred Duncan, an F. B. I. agent investigating the growing number of mutants. Xavier told Duncan of his plan to locate young mutants and enroll them in his "School for Gifted Youngsters" using his ancestral mansion home as a base to train them to use their powers for humanity's benefit. Over the following months Xavier assembled his original team of "X-Men:" Cyclops, Iceman, Angel, Beast, and Jean Grey, who took the name Marvel Girl.

Years later, when most of his original students were captured by the mutant Krakoa, Xavier recruited a new team of X-Men, including Banshee, Colossus, Nightcrawler, Storm, and Wolverine. In subsequent years he added more members to the X-Men, such as Rogue.

Lilandra, princess of the alien Shi'ar race, came to Earth to ask Xavier for his help against her tyrannical brother D'ken. Xavier and Lilandra fell in love, and for a time he lived on Chandilar, the Shi'ar throneworld, as her consort.

The alien race called the Brood had secretly implanted an egg within Xavier's body. MacTaggert and the X-Men's spacefaring allies, the Starjammers, saved Xavier by transferring his mind into a newly cloned, somewhat younger body in which he could once again walk. But in subsequent months Xavier suffered physical injuries and psychic strains that left him on the brink of death. Lilandra and the Starjammers took him into outer space where they used Shi'ar technology to restore him to health.

After an extended sojourn in space with the Starjammers, Xavier finally returned to Earth. Both the original and second teams of X-Men reassembled under his leadership, along with new recruits like Gambit and Bishop. Xavier led the X-Men against the Shadow King, only to have his spine broken in battle, leaving him crippled and confined to a wheelchair once more.

Since the X-Men were all now highly trained adults, Xavier renamed the school in his mansion The Xavier Institute for the Gifted.