British Royal Family Arc

The British Royal Family Arc is a major story arc of the Toaru Majutsu no Index series. The arc focuses on a magical conflict in the United Kingdom, as Second Princess Carissa launches a coup d'état for the throne with the backing of the Knights of England. She is opposed by her sister Villian, who has the aid of Necessarius, including Index and Kamijou Touma, the two originally in England to investigate a magical attack on the Eurotunnel.

The end of this arc, as well as the next arc, would immediately segue into the final arc of the Toaru Majutsu no Index light novels. In this arc, the end of the civil war is marked with Kamijou's first confrontation with Fiamma of the Right, who had taken advantage of the chaos to steal a relic that control Index and grants him access to the Grimoires in her memory. This is followed by Kamijou leaving Index in the care of Necessarius as he chases after Fiamma into Russia, alone.