Charles was originally referred as The Emperor of Britannia, and his name was not mentioned until later on. He is the father of Nunnally and Lelouch vi Britannia, Cornelia and Euphemia li Britania, Carine le Britannia, Clovis la Britannia, Odysseus eu Britannia, Guinevere su Britannia, and Schneizel el Britannia. He is the 98th Emperor of the Holy Britannian Empire, and the younger brother of V.V. He believes that equality is evil and most be destroyed so he encourages class conflict and military expansionism to maintain his ideals. He is willing to use his children to accomplish his goals, as he sent Lelouch and Nunnally to Japan as political hostages during the Sakuradite conflict after their mother died. He will test his children on their leading ability by giving them important positions throughout Britannia.

His main goal is to invoke Ragnarok(*) which would remake the world into a place with no lies. To do this he must use the Sword of Akasha, a weapon designed to kill "God", which is C's world, the collective unconsciousness of all mankind. But he must also have help, from the two people with the code, V.V. and C.C. but the 98th empress Marianne vi Britannia wanted to help also, she got C.C. to join, and was at that moment in charge of the Geass Order. But V.V. did not live to see any of this happen, so the one who had the second code was Charles himself. Lelouch thinks that the idea is stupid and will make life worse, and Lelouch then uses his Geass to turn C's world on Charles, which killed Charles and Marianne. Charle's dying words where that it would be Schneizel's world that will await him.

Just how did Charles zi Britannia get the Code? Charles originally had Geass, which allowed him to rewrite someone's memories. A few examples are: Anya Alstreim the Knight of Six, who was the only true witness to Marianne vi Britannia's first death, had the incident wiped from her consciousness. Nunnally vi Britannia was the cover up witness, also had a few things wiped from her consciousness but became blind afterwards. Lelouch vi Britannia, after Suzaku Kururugi brought him to the emperor as Zero, he lost all memories of ever being Zero, and Lelouch vi Britannia, so he no longer knew that he was royalty, instead there were fake memories placed. Finally the members of the student council all forgot about Nunnally. He got his geass from his older yet younger brother V.V.