Professor X

Charles Francis Xavier was the only son of Brian Xavier, a nuclear research scientist and his wife Sharon. Brian died while Charles was still a young boy and Sharon eventually married Brian's colleague, Kurt Marko. Marko also had a son from a previous marriage named Cain, and as the older step-brother, Cain made Charles life miserable. While still a child, Charles discovered that he was a mutant and possessed the ability to read minds. Charles spent years learning to control his abilities and did not use them for his own gain, but used them in benevolent ways.

While at Oxford University, Charles met and fell in love with a fellow student named Moira McTaggert. The two were engaged to be married, when Xavier was called into service as a soldier in Asia, so the marriage arrangements were put on hold. Xavier and his step-brother Cain were put in the same unit, so Xavier was there on the day that Cain broke into an ancient temple and discovered the mystic artifact called the Ruby of Cyttorak. By touching it, Cain Marko was endowed with the mystic power of the ruby and became the unstoppable Juggernaut. Xavier and Marko were separated by a cave-in and Xavier escaped.

Upon being released from service, Xavier found that McTaggert had broken off their engagement without reason. Saddened by the news, Xavier decided to travel for a while to take his mind off his personal problems. While traveling in Cairo, Xavier encountered his first fellow mutant, an evil man named Amahl Farouk. Farouk was a mutant of great telepathic ability and fought Xavier in the astral realm. Though the Farouk was more experienced in battle, Xavier was able to defeat him. Through this experience, Xavier came to realize that there were those who would not be as selfless as he with their powers and decided that he would use his powers to oppose those who would exploit their abilities for evil purpose.

From Cairo, Xavier traveled to Israel, where he met two people that would have a huge impact on his life. The first was Gabrielle Haller, a woman with whom Xavier had an affair which produced a son David. Xavier did not know of the child for many years. The other person was a fellow mutant name Erik Magnus Lehnsherr. The two became fast friends, but differed on the how mutants should act in the world. Lehnsherr believed that mutants should use their abilities to seize their rightful place as the dominant species over normal humans, while Xavier believed in a philosophy of peaceful coexistence. The difference between these two philosophies would be the basis for years of conflict between Xavier and those who followed him and Lehnsherr who adopted the name Magneto and those who followed him.

Xavier soon found himself defending humanity from an attack from an extraterrestrial menace. An alien who called Lucifer was attempting to invade the Earth, but his efforts were thwarted by Xavier's vast mental powers. The fleeing alien struck back on Xavier by dropping a large stone upon him. Xavier's resulting injuries crippled him and confined him to a wheelchair.

Xavier returned to the United States and decided to use his abilities to train mutants in the use of their powers. His first student was a young girl named Jean Grey whose mutant powers were jumpstarted when she was still a child, when she experienced telepathically the death of one of her friends. Xavier was able to use his telepathy to heal Grey's mind and then block her abilities until she was old enough to control them.

Setting up a school in his home in Westchester, New York, Xavier began to collect young mutants who needed help controlling their abilities. The original five became known as the X-Men and served to further Xavier's dream of peaceful co-existence between humans and mutants often times by opposing mutants who attempted to use their powers for evil. Xavier often coordinated the X-Men by using his powers to direct the team from afar. It was at this time that he took the codename Professor X.

Soon, Xavier found evidence of another invasion from space and decided that he needed time away from his students to prepare to repel the invaders. He approached a mutant codenamed the Changeling about taking his place for a time. The Changeling agreed, but soon after switching places, the Changeling was killed in battle, leaving the X-Men to believe that Xavier had been killed. Xavier later revealed the ruse to his students, who were quick to forgive him, when they found out the reason why.

After the original X-Men disappeared, Xavier used his mutant detecting computer Cerebro to locate a new group of mutants to assist him in finding his lost students. This new group soon became his students and the new X-Men. He helped to train them for a time, but soon believed that he was losing his mind as he began to have visions of an alien woman. The woman turned out to be the leader of the Sh'iar empire, Lilandra, who came to Xavier hoping that he and his students could assist her in defeating her mad brother D'Ken. Xavier and the X-Men assisted her in stopping him and Xavier spent some time with Lilandra and was named her consort.

When the X-Men were off world and believed killed, Xavier began to train a new group of mutants who he named the New Mutants. These younger students stayed on even after the X-Men returned to Earth. It was during this time that it was revealed that the alien species the Brood had implanted Xavier with an egg. With the help of Lilandra and the medical equipment supplied by the Starjammers, Xavier's mind was transferred into a cloned body which was younger and did not possess the injuries of his older body and so therefore, could walk.

Xavier took a more active role in the X-Men's missions for a time, but a series of events took a mental and physical toll on the mutant leader. He was taken by Lilandra and the Starjammers back into space and spent some time recuperating with them. Upon his return, Xavier fought his old foe Amahl Farouk the Shadow King and during the resulting battle, Xavier again sustained injuries that caused him to lose the use of his legs.

Over the next couple of years, Xavier again lead the X-Men, but after an episode in which Xavier used his mutant abilities to shut down the mind of Magneto, Xavier found that he was losing control of his abilities. The contact with Magneto's mind caused Xavier to manifest all of the evil impulses within him into a being constructed of mental energy called Onslaught. Onslaught was eventually defeated by the combined efforts of the Avengers, Fantastic Four, and X-Men with the victory seemingly costing the world the lives of the Avengers and Fantastic Four.

Because of his involvement in the creation of Onslaught, Xavier was taken into federal custody and came into the hands of the Master Mold-reborn, Bastion. Xavier was able to hide that he still possessed his mutant powers, but he disappeared for a time and eventually returned to the X-Men in time to help defeat his creation Cerebro. Xavier has lately announced to the world his identity as a mutant and heads the cause of mutants world wide.

In the film version of the X-Men, Xavier was portrayed by Patrick Stewart.