The story of Code Geass revolves around the life of one man, Lelouch Lamperouge. His true identity is Lelouch vi Britannia, the 11th Prince of the Britannian Imperial Family.
Because of the assassination of his mother and the crippling of his sister, Nunally, Lelouch sought to create a better world for her. C.C. gives him the power of the Geass in order for him to command others to behave as he wishes. He also creates his alter-ego, Zero, to destroy Britannia and rebuild it.
CODE GEASS
Lelouch Lamperouge is the title character and protagonist of the series. He was born as Lelouch vi Britannia, the Eleventh Prince of the Britannian Imperial Family and seventeenth in line for the throne. His father is the Britannian Emperor, Charles di Britannia, and his mother was Marianne vi Britannia. He was sent to Japan as a political hostage for questioning his father's cold regard for his mother's assassination and the crippling of his sister Nunnally. When Brittania invaded, he went into hiding with his sister, taking refuge with the Ashford family. Seven years later, he obtains an ability known as Geass, which allows him to compel others to behave as he wishes. Seeking to build a better world for his sister, he pursues the destruction of Britannia under his alter-ego — Zero.