Extracted from the article: Earth Federation
With the destruction of the political balance that was held during Reconstruction, the Tech Infantry feared a return to the days of Technocracy rule. In order to prevent this, Marshal Sarah Dunmeyer attempts coup in late 2242 and fails. Half of the military joins with her to form a faction later referred to as theTech Infantry Rebels. The Resistance and Christian Federation factions emerge to take advantage of the chaos and neighboring countries invade to take Fed systems.
As the Tech Infantry Rebels struggles for supremacy, Sarah Dunmeyer is assassinated and replaced in a coup by General Joel Fabin. Together, they push to crush the Grand Council Loyalists in the Battle of Avalon and fail. The TI faction never recovers and is finally finished off by a combined assault of K'Nes, Jurvain, and Eastern Bloc forces. The Resistance and Christian Federation upstarts are also summarily destroyed. Arthur Clarke is named the new Chairman of the Earth Federation after the Grand Council is assassinated and he imposes a draconian order called the Five Acts. The war ends in 2244 with the Treaty of Wilke's Star and Clarke demands status quo ante bellum. The other powers refuse, but were too weak to continue the fight. Finally, all sides agreed at fixing the borders on ceasefire lines.
Behind the Scenes
The 3rd Civil War was the campaign setting for Season 4.3.