Cornelia li Britannia was the second princess of the Holy Britannian Empire
After the revelation that Lelouch was Zero, Cornelia was found by Suzaku. Cornelia promoted Suzaku to the status of full knight, before being evacuated minutes before Operation Nero was carried out. However, Cornelia never recovered mentally. She transferred to the Pendragon Royal Guard, and became more secluded and isolated. After Lelouch was brainwashed into rejoining the Royal family, Cornelia showed hostility to him. When the Black Knights launched a surprise raid, Cornelia faced off with Kyoshiro todoh; though the battle technically ended in a draw, the Black Knights were successful in their primary mission.
Later, she confessed to Guileford that she never forgave herself for being hostile to Euphemia in their final talk, and swore to kill Zero.