Knights of the Round

The Knights of the Round (ナイトオブラウンズ, Nait ō bu Raunzu) or formerly known as the 12 Horsemen is a unit of twelve elite soldiers in the Holy Empire of Britannia, each being assigned into the group by royalty and under direct command of the Emperor. The Knights of the Round extends to at least the 18th century, with the first Knight of One being Sir Richard Hector. Named after the Arthurian Knights of the Round Table, they operate outside the standard Britannian military and are given special privileges and authority.

Privileges
Aside from the Knight of One, there were no known distinctions in privileges between the numbers as they existed in the era; however, all Knights of the Round are given a higher rank than many nobles, excluding members of the imperial family. Regardless of birth as a Britannian commoner or a Number, all members of the Knights of the Round are given a form of authority as seen with Suzaku who ordered Lloyd, an Earl, to give him the Lancelot Albion. During Lelouch's era, nobility is no longer awarded to the Knights of the Round and all of its' members were stripped of their nobility. However, all Knights of the Round were still given a high position of authority in the Britannian military.

The Knight of One may request governance of any colonial area of his choosing from the Emperor. After a person is captured for assaulting a knight, the knight can then decide the fate of the captured person, as seen after an attempt to assassinate Suzaku by an Eleven; he was asked for the severity of the punishment for the Eleven. Only eight of the twelve Knights have been revealed. The Code Geass novels explain that not all of the seats are filled, so those featured might be the only active members. A Knight of the Round cannot be punished for his crimes by anyone other than the Britannian Emperor, as shown when Schneizel was unable to punish Suzaku for meeting with Lelouch behind his back.

A special title, the Knight of Zero, was created by Lelouch vi Britannia following his ascension to the throne. This title was specifically given to Suzaku Kururugi, who was thereby classified as a Knight of the Round above all others, giving him the highest authority as a Britannian Knight, even over the Knight of One. This name is also a double entrendre, as the Knight of Zero suggests that he is Zero, or Lelouch's knight, and he is higher than the Knight of one, which going by the numbering order, zero would be higher than one in this case.

Current Members
Suzaku Kururugi, Anya Alstreim and Gino Weinberg are the only Knights of the Round members who are confirmed to have survived the events of the series.

Aftermath
By the end of the anime, it is assumed that only four of the Knights of the Round, from Charles zi Britannia's era, are currently alive. Suzaku Kururugi lives as the new Zero, assisting empress Nunnally in remaking Britannia. Gino Weinberg resumes attending Ashford Academy as part of the Rivalz's Student Council. Anya Alstreim was seen cultivating an orange farm with Jeremiah. Nonette Enneagram is presumably alive as she did not join with Bismarck Waldstein in the failed attempt to overthrow Lelouch nor did she participate at the Battle of Mt. Fuji.

Code Geass: The Manga
Knights of the Round have lesser emphasis in the manga due to the appearance of Suzaku, Gino, and Anya. They appear to have dissolved due to Emperor Lelouch's ascension to the throne as well as after Zero Requiem.

Nightmare of Nunnally
In the manga Spinoff Nightmare of Nunnally, a group of former knights of the kingdom are revived by Charles zi Britannia's Geass "The Dead Rise." They each pilot Sutherland Sieg-like Knightmares. The only named member of this group is Bismarck Waldstein.

Lost Colors
In the Spinoff game, Code Geass: Lost Colors, Nonette Enneagram appears as a Knight of Round and acts as a mentor to the protagonist character. Her appearance in Code Geass R2 is a salute to her appearance in the game, despite not having any role in the anime.