- "Lelouch the demon is dead! Free his prisoners."
- ―Cornelia, after Lelouch's death.
Cornelia Li Britannia is a major antagonist of the anime series Code Geass: Lelouch of the Rebellion serving as the main antagonist of the first season. She's the Second Princess of the Britannian Imperial Family and of the Holy Britannian Empire and later becomes the Viceroy of Area 11 after Clovis la Britannia is killed.
She was voiced by legendary voice actress Mary Elizabeth McGlynn.
Second Princess Cornelia first appears in episode five, having establishing Area 18 and then arrives at Area 11 to take over as Viceroy after Third Prince Clovis's death. She intends on bringing Zero, the number one enemy to the Holy Britannian Empire, to justice in order to avenge Clovis. After entering Area 11, Cornelia continues her hunt for Zero. She destroys several rebel strongholds, but discovers no clues of her targets whereabouts. She attends Prince Clovis' funeral and hears the Emperor of Britannia, Charles zi Britannia, made a speech on the virtues of inequality and the social battle for evolution and betterment.
Cornelia sets a trap for Zero at the Saitame Ghetto by simulating the conditions in the Shinjuku Ghetto. She thought Zero would take the bait due to the combination of Cornelia's superior tactics and the Resistance Cell's dissimular motivations. Just when she thought Zero was finally cornered, C.C. appeared in Zero's costume which distracted Cornelia from her plans, allowing Lelouch to escape. Later, a group of members of the Japan Liberation Front led by Lt. Colonel Josui Kusakabe takes a hotel and its occupants hostage including a disguised Princess Euphemia and members of the Ashford Academy Student Council. Cornelia refuses to take action with the fear of endangering her little sister, which Zero realizes and takes advantage of. He mounts a rescue mission with Ohgi's group to eliminate Josui and his men and rescue the hostages. Ordered by Cornelia, Suzaku sinks the hotel using his Lancelot. Although Zero denies any of the Army's rescue efforts so he and his group can take the credit. In his broadcast, Zero makes announces he has formed the Black Knights and described them as "allies of justice" who will judge the world and protect the weak from those with power. Cornelia refuses to attack Zero as she fears the masked man will take Britannians as hostage.
During the Battle of Narita, Cornelia leads the attack on the Black Knights along with both Britannian Generals Darlton and Guilford. Guilford warns her to stay away and she responds by destroying several Burais. After the landslide created by Kallen's Guren, Cornelia is more worried about Andreas Darltons and her other subordinates than her own saftey. She is then informed of the Black Knights entered the battlefield. She is then seen retreating, but Kallen stops the Princess with her Guren. Zero has her cornered while in his Burai, and Cornelia shoots at Kallen but misses. She then uses her Gloucester's Slash Harkens to cling to the cliff side. Zero's Knightmare Frame shoots her back down. Zero demands Cornelia to surrender and she responds by trying to impale the Guren with her lance. The Guren uses the Radiant Wave Surger to destroy the right arm of her Gloucester. Zero shoots off the left arm. She tells her Knight, Guilford, to protect Euphemia and that she will fight like a royal princess. Suzaku's Lancelot shows up to protect Cornelia and tells him to hold off the Guren while she goes after Zero. After the battle between the Guren and Lancelot she instructs Suzaku to go after Zero since her Knightmare has collapsed.
Concerned about her young sister, Cornelia convinces Euphemia to get her personal Knight. Though the Princess finally chose her knight, Corenelia began to worry again when Euphemia selects Honorary Britannian, Suzaku Kururugi. Cornelia's worries get worse when Sub Viceroy Euphemia's saftey only increase when Euphemia proposes and establishes the Special Administrative Zone of Japan, a plan Cornelia opposes to but lets her do so and sends Darlton to oversee it. Following Princess Euphemia's death, Cornelia vows to take down Zero and the Black Knights. She almost succeeds during the First Battle of Tokyo, outmanoevuring and repeatedly scoring hits on Zero's supposedly superior Gawain unit, before Darlton, under Geass disables her Gloucester and wounds her. Lelouch initially plans to use her as a hostage to force the opposing Britannian Military to surrender but is thwarted by the enraged Jeremiah Gottwald. She remains wounded on top of the government bureau and declares Suzaku Kururugi as a knight and sends him after Zero.
After the end of the First Black Rebellion, Cornelia goes missing and leaves Area 11 in search of evidence to prove that Euphemia is innocent and ends up discovering the power of geass. She makes it to the Chinese Federation where she comes across the headquarters for the Geass Order in an attempt to finally destroy the power once and for all. During this time, she comes across Bartley Asprius who reveals himself to be a pawn of the order and is later captured as well.