The Rise of the Red King series was a fanfiction series, that takes place following the events of Code Geass R1, with a number of alternatives implemented in the storyline. The story diverges from the events of the Black Rebellion.
The Black Rebellion has failed, the Battle of Tokyo ended with a new Britannian offensive and the Black Knights withdrawing, Zero has been captured by Sir Suzaku Kururugi. As the Black Knights and other Rebels flee, and regroup, Lelouch vi Britannia was brought to heel before Charles zi Britannia. He lost everything, stripped of his memories and knowledge, of all he loved and treasured.
The Black Knights succeed against adversity however, led by a committee and guided by C.C. they reform in the Hokkaido region, using hidden bases and checkpoints in the region to check and destroy Britannia's hunting parties for them. A scheme at work spearheaded by Kallen Kozuki and C.C. seeks to save Zero, to once more use his strategic genius to destroy Britannia.
However, a new threat is on the rise, as Byakko von Britannia takes centre stage to lead the Knights of the Round from the front-line.