Extracted from the article: Earth Federation.
In 2223, with the death of Fialla Spencer, who was a mediator between the Harrington and Triumvirate factions, the 2nd Triumvirate moved to finally eliminate Harrington's power. With the Bugs eliminated from all known systems (save Fieras), the Grand Council ended its military contracts with the Ferret Works, a Harrington company. With their cash flow weakened, the Triumvirate promoted a scandal with Lwan Eddington, who was imprisoned on G2 for having an affair with Brigette Campbell, another officer. With her monetary and military connections severed, the Triumvirate moved to break up Harrington Industries under anti-trust legislation (recently passed in the Senate). Seeing the endgame of the Triumvirate, Maeve felt she had no choice but to stop them by any means necessary. She threw her corporation's support to the Liberation and open war was declared.
The 2nd Triumvirate is toppled through the Liberation's efforts. Colonel Richard Fox is supposedly killed by Liberation bomb; rumors abound of his escape. Senator Samuel Wall mysteriously disappears soon after. Colonel Arthur Clarke, unable to maintain control of the Federation without his partners, allows the Tech Infantry leadership to assume control of Earth Federation.
They proceed to eliminate all opposition. In 2225, since the Liberation is decentralized, they assault on the Sabbat at Wilke's Star Brigadier-General Sarah Dunmeyer turns a potential tragedy into a costly victory. The next year, under Major-General Hadrian Gartvo's campaign, the Liberation begins to lose ground to TI assaults. As the Federation is concentrating on the core systems, the border worlds declare their independence and form the Frontier Worlds Territory.
Maeve Harrington, desperate to save her company and family, betray the Liberation. She is assassinated soon after. The Liberation is destroyed at the cost of leaving the Federation in shambles. Desperate to stabilize their borders, the Fed recognizes the FWT as a legitimate state. By 2228, the Tech Infantry hierarchy relinquishes control of Federation to a new civilian government. See also 3rd Civil War.
Behind the Scenes
The 2nd Civil War only occurs in the background - it was never actually played out. When Marcus was setting up Season 4.1 , he was trying to resolve the situation that Penny set up at the end of Season 3 (Part 2). Since there is a gap of 20 years between two seasons, Marcus had to explain what happened to the 2nd Triumvirate, what happened after Lwan Eddington was disgraced, and set up how the new factions came to be. So although he was a bit unfair to the old PC's, uber-powerful NPC's are really hard for the new players to match.