The Holy Empire of Britannia is ruled by the Britannian Imperial Family (皇室, Kōshitsu), with its members holding the highest positions within its government and military. The Imperial Family are descended from Sir Ricardo von Britannia, the designated heir and lover of Queen Elizabeth III.
Each of member of the Britannian Imperial Family is ranked by both birth order and inheritence. As an example of birth order, Clovis is the Third Prince while Lelouch is the Eleventh Prince, making them Charles' third born and eleventh born sons. Lelouch's mother, Marianne, was the Emperor's Fifth Empress. The numbering of the Imperial princes and princesses is separated by gender; for example, Euphemia is the Third Princess and Clovis is Third Prince. The order of succession appears to be male-preference primogeniture, though the number of children and precise inheritence is difficult to determine. Lelouch himself is both 11th Prince and 17th heir to the throne, and while this six place gap can be explained by Lelouch having a number of nieces and nephews, but there is no evidence for this, either way. However, Nunnally's rank in the order of succession, as 87th, strongly suggests that Charles has many, many sons who are younger than Lelouch.
However, this presumed order of succession has been contradicted both in canon, and out of it. Lelouch becomes 99th Holy Britannian Emperor through force of arms and the power of Geass, ignoring that many of his brothers yet live. Nunnally's ascension to the throne lies in a gray area. As the closest living relative to the deceased Emperor Lelouch, she has a defendable position as Heir Apparent. However, her elder half-siblings would also have a point to argue from, as a genetic relationship to her mother, Marianne, would not be a major consideration in choosing the next Emperor. Though of the siblings introduced in the series, only Cornelia retains the mental ability to argue the point by series' end. Some spin-off manga do this to a greater degree, with Nightmare of Nunnally having Euphemia elected Empress over many of her siblings for no specified reason, and Oz the Reflection unveiling Maribelle, a princess older than Nunnally, yet lower ranked in the succession than she.
The princes and princesses use the same nobility particle as their mother, though the usage does not mirror any real-world method. Each member of royalty is entitled to elect a personal guardian called a "Knight," who are given authority and placed directly under their command, though only Cornelia and Euphemia are shown to have done so, other than the Emperor. Cornelia's Knight is Guilford who, along with her, commands a unit of Knightmare Frames. Suzaku Kururugi also served as personal Knight to both Euphemia and Lelouch (as the Emperor of Britannia), donning the title "Knight of Zero" in his service with the latter.
Britannian Imperial Family
|Charles zi Britannia (98th Emperor) - (Deceased)|
|Lelouch vi Britannia (99th Emperor/Eleventh Prince) - (Deceased)|
|Nunnally vi Britannia (100th Empress/Fourth Princess)|
|Odysseus eu Britannia (First Prince) - (Status unknown after the incident in Pendragon)|
|Guinevere su Britannia (First Princess) - (Status unknown after the incident in Pendragon)|
|Schneizel el Britannia (Second Prince)|
|Cornelia li Britannia (Second Princess)|
|Clovis la Britannia (Third Prince) - (Deceased)|
|Euphemia li Britannia (Third Princess) - (Deceased)|
|Carine ne Britannia (Fifth Princess) - (Status unknown after the incident in Pendragon)|
|Marianne vi Britannia (Fifth Imperial Consort) - (Deceased)|
|Gabrielle la Britannia (Imperial Consort) - (Status unknown after the incident in Pendragon)|
|Charles' Father (First Prince) - (Deceased)|
|Alec la Britannia (91st Emperor) - (Deceased)|
Other Members of the Imperial Family
The following includes members of the Britannian Imperial Family who appear in side-stories and other material related to the Code Geass series. Some members may be non-canonical to the primary Code Geass timeline.
Video Game Characters
Castor rui Britannia (キャスタール・ルィ・ブリタニア, Kyasutāru ru~i Buritania) and Pollux rui Britannia (パラックス・ルィ・ブリタニア, Parakkusu ru~i Buritania) are a pair of twin princes introduced in the Code Geass video game for Nintendo DS. Repeat playthroughs of the storyline add them as new antagonists to allow the recruitment of Cornelia and Euphemia, as well as certain other Britannian officers.
The princes are both Knightmare Frame pilots; Castor pilots the Knightmare Frame Equus and his brother pilots the Knightmare Frame Aquila. They both also possess a unique Geass ability. While Pollux uses an inferior version of Lelouch's power, Castor's ability allows him to telepathically communicate with his twin brother. To Pollux's annoyance, he is frequently mistaken for his brother.
The brothers are named after the Castor and Pollux, twin brothers from Classical mythology who becomes identified as the twins in the constellation of Gemini.
Claire le Britannia is the princess of Britannia during Japan's Edo era, originally sent to Japan at a young age by her parents to avoid being harmed by the conflict amongst the members of the Imperial Family. In Japan, she resided in a hidden village of fallen Japanese nobles under the alias of "Carla".
Her identity is later revealed to her friends when Andreas Weinberg arrives in Japan with the purpose returning Claire to Britannia as its next empress.
Maribelle mel Britannia is a Britannian Princess and the 88th in-line to the succession of the throne. She is the founder and leader of the Glinda Knights, a counter-terrorism organization within the Britannian military. Though she appears gentle and refined, she personally serves on the frontlines as the captain of the Granberry, the Glinda Knights' floating airship. Thanks to her keen strategic abilities, she gained the favour of Second Prince Schenizel, who granted her priority use of any prototype machines developed by Camelot for the Knights of Rounds.